KR20130060508A - System and method of measuring contact angle and coating condition of ink, and ink-jet printing apparatus having the same - Google Patents

Abstract

PURPOSE: A system and a method for measuring an ink contact angle and an ink spread state, and an inkjet printer with the same are provided to check the ink contact angle and the ink spread state of a specific region where failure frequently occurs. CONSTITUTION: A system and a method for measuring an ink contact angle and an ink spread state comprises an inkjet head(220), a first measuring camera, one or more second measuring cameras, and a control device(290). The inkjet head is positioned on a substrate(210) and discharges ink droplets(228) on the substrate. The first measuring camera is positioned on the lateral surface of the substrate and obtains first images of the ink droplets. The second cameras can be stopped and moved to several positions on the substrate and can obtain second images of the ink droplets spread on the substrate. The control device receives the first and second images from the first camera and the second measuring cameras, respectively, thereby measuring the ink contact angle and the ink spread state of the ink droplets.

Description

TECHNICAL FIELD The present invention relates to a system and method for measuring ink contact angle and coating state, and an ink-jet printing apparatus having the same.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system and method for measuring an ink contact angle and an application state, and an inkjet printing apparatus having the same.

More specifically, the present invention directly measures the contact angle and the application state of the ink applied onto the substrate by directly measuring the contact angle and the application state of the ink applied on the substrate when the ink is applied using the inkjet printing apparatus Therefore, it is not necessary to use a separate measuring instrument. Therefore, in the case of a large-area substrate, the user can check the contact angle and the coating state of the ink for each specific region. If the application condition of the ink is not matched, The contact angle and the application state of the ink can be changed so as to quickly adapt to the new application conditions of the ink in the field even when the application conditions of the ink are changed and the total process time (tact time) A system and method for measuring ink contact angle and application state in which the probability of occurrence of defects is significantly reduced, Keujet relates to a printing apparatus.

Generally, in order to manufacture an electronic circuit component or a flat panel display (FPD) such as a plasma display panel (PDP) or a liquid crystal display panel (LCD), for example, a photoresist Such as electrodes or dots, on a glass surface or a printed circuit board (PCB) using a metal paste such as copper (Cu), silver (Ag), aluminum Constant patterns should be formed.

As a method for forming the above-described constant pattern, for example, there is a method of directly patterning a certain pattern by an offset printing method using two rolls or an inkjet printing apparatus having an ink jet head for ejecting ink droplets A method of directly printing a certain pattern is used.

1A is a perspective view of an inkjet printing apparatus according to the prior art.

Referring to FIG. 1A, a conventional inkjet printing apparatus 100 includes a plurality of inkjet heads 120 for supplying ink to form a plurality of patterns 114 on a substrate 110, for example. A gantry (130) on which the plurality of inkjet heads (120) are mounted and movable on the substrate (110); And an ink storage device 150 connected to the plurality of inkjet heads 120 to provide ink. Hereinafter, the operation of the conventional inkjet printing apparatus 100 will be described in detail.

Referring again to FIG. 1A, in the inkjet printing apparatus 100, a plurality of inkjet heads 120 are provided with an ink supply main conduit 152 and a plurality of branch conduits 152a, 152b, 152c, 152d, ..., 152e. The start and end of the ink supply is controlled by the plurality of control valves 156a, 156b, 156c, 156d, ..., 156e. The pressing force of the ink storage device 150 is provided by a pressurized fluid (for example, air) supplied from the ink pressurizing conduit. The supply of the pressurized fluid is controlled by the pressurized fluid control valve 154. The gantry 130 on which the plurality of inkjet heads 120 are mounted is moved on the substrate 110 to supply ink onto the substrate 110 to form a desired plurality of patterns 114. [ The substrate 110 is placed on a stage 112 for fixing the substrate 110 and the stage 112 is placed on the printing apparatus frame 160. [

Fig. 1B is a view for explaining a thermal ink-jet head and operation used in the ink-jet printing apparatus according to the prior art shown in Fig. 1A in detail.

Referring to FIG. 1B, the thermal inkjet head 120 according to the prior art exemplifies any one of the plurality of inkjet heads 120 according to the prior art shown in FIG. 1A. In the thermal inkjet head 120, when an electric power pulse is applied to the heater 122, the ink in the chamber 124 instantaneously receives heat and expands to form a droplet 110a ). ≪ / RTI > Therefore, when the plurality of inkjet heads 120 shown in FIG. 1A are the thermal inkjet heads 120 shown in FIG. 1B, respectively, the droplets 128 of the ink are applied to the instantaneous heating of the heater 122 as described above And is sprayed through the nozzle 126, so that a desired plurality of patterns 114 are formed.

Fig. 1C is a view for explaining a piezo ink-jet head and its operation for use in the ink-jet printing apparatus according to the prior art shown in Fig. 1A.

Referring to FIG. 1C, the piezo inkjet head 120 according to the prior art exemplifies any one of the plurality of inkjet heads 120 according to the prior art shown in FIG. 1A. In the piezo inkjet head 120, a piezoelectric element 121 attached to the head 120 is deformed by a piezoelectric driver (driver) 123. The applied deformation vibrates the meniscus 124 in the head 120 so that ink is formed and ejected from the nozzle 126 of the head 120 into the droplet 128.

In the inkjet printing apparatus 100 according to the above-described prior art, the ink used in the plurality of inkjet heads 120 is usually made of various kinds of photoresist (PR) liquids or metal pastes "). In addition, the nozzles 126 of the ink jet head 120 have a narrow size of approximately several to several tens of micrometers (for example, 20 micrometers) in diameter.

The specific structure and operation of the inkjet printing apparatus 100 of the prior art as described above are described in detail by the present applicant on Apr. 17, 2008 in "a complex system having an inkjet printing function and an inspection function, and an inkjet printing apparatus "Filed as Korean Patent Application No. 10-2008-0035827, and Korean Patent No. 10-0987828, filed on Oct. 7, 2010, which is incorporated herein by reference.

In the conventional inkjet printing apparatus 100, ink is ejected onto the substrate 110 in liquid crystal form using an inkjet head 120 to form a plurality of patterns 114. In this case, a method for measuring the contact angle of the ink applied on the substrate is used as a method for confirming the application state of the ink.

More specifically, FIG. 1d is a schematic view of a system and method for measuring the contact angle and the application state of ink according to the prior art.

1D, in the ink contact angle and application state measuring system 170, a small sample glass 110a is disposed on a second stage 172 provided separately from the inkjet printing apparatus 100 shown in FIG. 1A, And then ink is ejected using the ink drop device 174 provided on the top of the second stage 172 to form the droplets 128 of the ink. The droplet 128 of the ink on the sample substrate 110a is then transferred to the droplet 128 of the ink captured by enlarging the droplet 128 of the ink by the measuring camera 180 located in the lateral direction of the second stage 172 And transfers the image of the obtained droplet 128 of ink to a control device 190 implemented by a personal computer or a microprocessor or the like. The control device 190 may analyze the image of the droplet 128 of the ink to measure the contact angle and the application height of the droplet 128 of the ink. When the contact angle of the droplet 128 of the measured ink and the height and width (hereinafter referred to as "coated state") fall within predetermined ranges, it is determined that the ink application state is appropriate, 100) is used to eject ink onto the substrate to perform a printing operation.

However, when using the above-described prior art ink contact angle and coating state measurement system 170, the following problems occur.

1. The prior art ink contact angle and application state measurement system 170 is a device provided and used separately from the inkjet printing apparatus 100 shown in Fig. 1A. Therefore, the ejection of the ink ejected from each of the ink drop device 174 used in the ink contact angle and coating state measurement system 170 and the plurality of inkjet heads 120 used in the inkjet printing apparatus 100 shown in Fig. It is difficult to keep the conditions the same. The contact angle and the application state of the ink 128 measured by the ink contact angle and the application state measurement system 170 and the contact angle of the ink 128 on the substrate 110 using the plurality of inkjet heads 120 of the actual inkjet printing apparatus 100 The contact angle and the application state of the derived ink may be different from each other. In this case, defects may occur in the pattern 114 finally formed.

If a defect is generated in the finally formed pattern 114, the ink ejection conditions of the ink drop device 174 used in the ink contact angle and the coating state measurement system 170 may be changed again, The measurement operation of the contact angle and the application state of the same ink should be repeated.

Therefore, in the prior art, there is a problem that the time required for the pre-process for setting the ink application condition is considerably long.

2. Also, the sample substrate 110a used in the ink contact angle and application state measuring system 170 of the prior art can be processed very uniformly throughout the entire substrate with a small substrate. On the other hand, the substrate 110 used in the actual inkjet printing apparatus 100 is difficult to uniformly process the entire surface of the substrate with a large or large area substrate, i.e., the substrate 110 is lower And has a flatness. Accordingly, even though the contact angle and the coating state of the ink are measured as appropriate in the sample substrate 110a, the contact angle and the coating state of the ink ejected onto the substrate 110 are partially appropriate depending on the surface condition of the substrate 110, May be improperly applied and a defect may be caused in the pattern 114 finally formed. Due to such a problem, the conventional art has a problem that the time required for the pre-process for setting the ink application condition is further increased.

3. When an external condition is changed (for example, when a new substrate 110 is used in which the used ink is changed to a new ink, or the surface state (flatness) of the substrate 110 to be used is changed over time) A measurement of a new contact angle with respect to a new ink or a new substrate by the prior art ink contact angle and application state measurement system 170 should be made. Accordingly, the above-described problems 1 and 2 continuously occur.

4. Due to the above-described problems 1 to 3, if defects are generated in the substrate, the ink ejected onto the substrate must be cleaned and reused. In addition, if the final product is defective, the expensive final product should be disposed of. Thus, the total tact time and cost are greatly increased.

Therefore, there is a need for a new method for solving the problems of the above-described conventional techniques.

Korean Patent No. 10-0987828

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems and it is an object of the present invention to directly measure the contact angle and the application state of ink applied on a substrate when applying ink using an inkjet printing apparatus, It is not necessary to use a separate measuring instrument. In the case of a large-area substrate, the user can check the contact angle of the ink and the application state of ink in a specific area, And to provide an ink contact angle and application state measurement system and method in which the total process time (tact time) and the possibility of occurrence of defective end products are remarkably reduced, and an inkjet printing apparatus having the same.

According to a first aspect of the present invention, there is provided a system for measuring the contact angle and the coating state of an ink, comprising: an ink jet head positioned on a substrate and discharging droplets of ink onto the substrate; A first measurement camera located on a side of the substrate and obtaining a first image of a droplet of the ink; At least one second measurement camera stationary or movable at a plurality of locations on the substrate, the at least one second measuring camera acquiring a plurality of second images of droplets of a plurality of inks applied on the substrate; And a controller for receiving the first image and the plurality of second images from the first measurement camera and the at least one second measurement camera and measuring the contact angle and the application state of the liquid droplet of the ink, do.

An inkjet printing apparatus according to a second aspect of the present invention includes: a plurality of inkjet heads for supplying ink to form a plurality of patterns on a substrate; A gantry on which the plurality of inkjet heads are mounted and movable on the substrate; An ink storage device connected to the plurality of inkjet heads, respectively, for storing ink to be supplied to the plurality of inkjet heads; A contact angle and ink application state measurement system for measuring the contact angle and the application state of the droplet of the ink; And a control device for controlling the operation of each of the plurality of inkjet heads, the gantry, and the ink storage device.

According to a third aspect of the present invention, there is provided a method for measuring an ink contact angle and an application state, comprising the steps of: a) acquiring a first image of an ink droplet ejected onto a substrate by a first measurement camera, To a control device; b) calculating a reference volume of the droplet from the first image using the control device; c) applying ink onto the substrate to form a plurality of patterns using a plurality of inkjet heads of the inkjet printing apparatus; d) acquiring a plurality of second images for a plurality of ink droplets deposited on the substrate at a plurality of locations on the substrate using one or more second measurement cameras, To a control device; And e) determining a coating diameter of each droplet of the plurality of ink droplets using the control device, and calculating a contact angle of each of the droplets of the plurality of ink droplets using the determined respective coating diameter and the reference volume, And calculating a height of the coating surface, wherein the coating condition is the coating diameter and the coating height.

The following effects can be achieved by using the ink contact angle and application state measuring system and method of the present invention and the ink jet printing apparatus having the same.

1. The contact angle and the application state of the ink applied on the substrate can be directly measured and confirmed in the field. Thus, unlike the prior art, there is no need to use a separate ink contact angle and application state measurement system.

2. In the case of a large-area substrate, it is possible to check the contact angle of the ink and the application state of the ink to a specific region where the user frequently generates defects. Further, it is possible to construct a database of a specific region in which defects occur frequently, and subsequently, to check the contact angle and the application state of the ink.

3. If the ink contact angle and application state are not suitable, rapid follow-up operation can be performed in the field. Further, even when the external condition is changed, such as when the ink used is changed to a new ink or when the surface state (flatness) of the substrate is changed over time and a new substrate must be used, The contact angle and the application state of the ink to the new ink or the new substrate in the field can be quickly changed to meet the new application conditions.

4. The total process time (tact time) and the possibility of failure of the final product are significantly reduced.

Further advantages of the present invention can be clearly understood from the following description with reference to the accompanying drawings, in which like or similar reference numerals denote like elements.

1A is a perspective view of an inkjet printing apparatus according to the related art.
FIG. 1B is a view for explaining a thermal ink-jet head and operation used in the ink-jet printing apparatus according to the prior art shown in FIG. 1A in detail.
Fig. 1C is a view for explaining a piezo ink-jet head and its operation for use in the ink-jet printing apparatus according to the prior art shown in Fig. 1A.
FIG. 1D is a view schematically showing a system and a method for measuring the contact angle and the application state of ink according to the prior art.
FIG. 2A is a view schematically showing a contact angle and an application state measuring system of ink according to an embodiment of the present invention.
2B is a perspective view of an inkjet printing apparatus according to an embodiment of the present invention.
FIG. 2C is a schematic view for explaining a method of calculating the contact angle and height of ink by the contact angle and ink application state measuring system according to the embodiment of the present invention shown in FIG. 2A.
FIG. 2D is an exemplary view illustrating a specific region on a substrate to which the ink contact angle and the application state measuring system according to the embodiment of the present invention shown in FIG. 2A are applied.
3 is a flowchart showing a method of measuring an ink contact angle and an application state according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described with reference to embodiments and drawings of the present invention.

FIG. 2A is a view schematically showing a contact angle and an application state measuring system of ink according to an embodiment of the present invention.

2A, an ink contact angle and application state measuring system 270 according to an exemplary embodiment of the present invention is disposed on a substrate 210 and discharges droplets 228 of ink onto the substrate 210 An inkjet head 220; A first measurement camera (280) located on a side of the substrate (210) and obtaining a first image of the droplets (228) of the ink; At least one second measurement camera 282 that is stationary or movable at a plurality of locations on the substrate 210 and that acquires a plurality of second images of droplets 228 of a plurality of inks applied on the substrate 210, ); And a controller configured to receive the first image and the plurality of second images from the first measurement camera (280) and the one or more second measurement cameras (282), respectively, And a control device 290 for measuring the state. Here, the controller 290 may be implemented by a personal computer, a microprocessor, or the like. Further, the ink jet head 220 may be any one of the plurality of ink jet heads 220 shown in FIG. 2B described later.

2B is a perspective view of an inkjet printing apparatus according to an embodiment of the present invention.

Referring to FIG. 2B, the inkjet printing apparatus 200 according to an exemplary embodiment of the present invention includes a system 270 for measuring the contact angle and the ink application state of the ink according to an embodiment of the present invention shown in FIG. 2A Is substantially the same as the prior art inkjet printing apparatus 100 shown in Fig.

Referring again to FIG. 2B, an inkjet printing apparatus 200 according to an embodiment of the present invention includes a plurality of inkjet heads 200 for supplying ink to form a plurality of patterns 214 on a substrate 210, (220); A gantry 230 on which the plurality of inkjet heads 220 are mounted and movable on the substrate 210; An ink storage device (250) connected to the plurality of inkjet heads (220) and storing ink to be supplied to the plurality of inkjet heads (220); A contact angle and ink application state measuring system 270 for measuring the contact angle [theta] and the application state of the droplet 228 of the ink; And a control device 290 for controlling the operation of each of the plurality of inkjet heads 220, the gantry 230, and the ink storage device 250. Here, the ink contact angle and application state measurement system 270 is implemented with the ink contact angle and application state measurement system 270 shown in FIG. 2A, in which case the control device 290 is configured And a control device 290.

FIG. 2C is a schematic view for explaining a method of calculating the contact angle and height of ink by the contact angle and ink application state measuring system according to the embodiment of the present invention shown in FIG. 2A.

Hereinafter, the specific configuration and operation of the ink contact angle and application state measuring system 270 according to an embodiment of the present invention will be described in detail.

Referring to FIGS. 2A to 2C, in the ink contact angle and ink application state measuring system 270 according to the embodiment of the present invention, when the ink jet head 220 discharges ink droplets 228 onto the substrate 210 , A first measurement camera 280 located on the side of the substrate 210 acquires a first image 228a of the droplets 228 of ink. This first image 228a is an image of the ink droplet 228 magnified and captured. Thereafter, the first measurement camera 280 transmits the first image 228a to the control device 290. [ Then, the control device 290 calculates the volume of the first image of the droplet 228 to make the diameter (2r) of the droplet 228 of ink from (228a) (V1) = ( 4/3) πr 3 . Herein, the volume V1 will be referred to as a reference volume RV.

Thereafter, ink is ejected onto the substrate 210 to form a plurality of patterns 214 using the plurality of inkjet heads 220 of the inkjet printing apparatus 200 according to an embodiment of the present invention shown in FIG. 2B Lt; / RTI > Thereafter, the one or more second measurement cameras 282 have a plurality of second images with respect to the droplets 228 of the plurality of inks applied onto the substrate 210 at the plurality of positions A, B, C, and D, respectively. Obtain 282a. Here, the plurality of second images 282a is an image captured by enlarging a plurality of droplets of ink 228.

On the other hand, for example, when the one or more second measuring cameras 282 are one second measuring camera, they sequentially move from position A to positions B, C, and D in sequence. Four second images 282a may be acquired. In addition, if the one or more second measurement cameras 282 are four second measurement cameras respectively positioned at the four positions A, B, C, and D shown in Fig. 2C, the four second measurement cameras are four. It may be provided in a stationary state at the two positions (A, B, C, D) to acquire four second images 282a at the same time. 2C, although a plurality of positions A, B, C, and D are illustrated as being four positions, those skilled in the art will appreciate that a plurality of positions A, B, C, And may be arbitrarily selected by the user.

In addition, since the droplets 228 of the ink actually have a very fine size, they can be regarded as forming a partial sphere on the surface of the substrate 210, as can be seen in the bottom view of Fig. 2C. have. The plurality of second images 282a obtained in this manner are transmitted to the control device 290. The control device 290 then confirms the application diameter 2D of the partial sphere of ink droplet 228 from the second image 228b. Thereafter, the volume V2 of the droplet 228 from the imaginary sphere S including the partial sphere of the droplet 228 applied onto the substrate 210 = (1/3) π (2R ³ 3R ² a + a ³ ). Since a = (R ² -D ² ) ^1/2 , the volume (V2) of the droplet 228 = (1/3) π (2R ³ -3R ² (R ² -D ² ) ^1/2 + (R ² -D ² ) is given by ^3/2 . Then, from the condition of the volume V1 of the droplet 228 of the ink before being applied on the substrate 210 = the volume V2 of the droplet 228 applied on the substrate 210, (4/3) πr ³ = (1/3) π (2R ³ -3R ² (R ² -D ² ) ^1/2 + (R ² -D ² ) ^3/2 is established, and the control unit 290 can calculate the unknown R by substituting the values of r and D measured at both sides. In addition, the controller 290 uses the calculated R value a = (R ² Calculate the a and H values, respectively, from the formula D ² ) ^{1/2 and} the formula H = (R-a). The result controller 290 then calculates the contact angle θ from the equation tan θ = D / a. In this manner, the control device 290 receives the first image 228a obtained from the first measurement camera 280 and the plurality of second images 228b obtained from the one or more second measurement cameras 282, and the application height H of the droplet 228 can be calculated. The coating diameter D 2 of the droplet 228 measured by the second measurement camera 282 and the coating height H calculated by the control device 290 indicate the application state of the droplet 228. The calculation of the contact angle? And the application height H of the droplet 228 by the control device 290 as described above can be performed by a calculation program stored in advance in the control device 290. [

As described above, by using the ink contact angle and the ink application state measuring system 270 according to the embodiment of the present invention, the ink jet head of the ink jet printing apparatus 200 according to the embodiment of the present invention shown in FIG. (I.e., the coating diameter 2D and the coating height H) of the droplets 228 of the ink discharged and applied onto the substrate 210 from the nozzles 220 can be measured.

When the contact angle [theta] and the application state of the droplet 228 of the ink measured in the above-described manner are within an allowable error range of a predetermined reference contact angle and a reference application state (i.e., a predetermined reference application diameter and a reference application height) It is determined that the ink application of the substrate 210 is appropriate. Thereafter, a plurality of inkjet heads 220 of the inkjet printing apparatus 200 according to an embodiment of the present invention shown in FIG. 2B are used for the subsequently supplied second substrate 210 to form a plurality of patterns The ink is applied onto the second substrate 210 so as to form the ink droplets 214. Thereafter, the plurality of second images of the droplets 228 of the plurality of inks obtained at the plurality of positions A, B, C, and D using the one or more second measurement cameras 282 as described above. As described above from 282a, the contact angle θ and the coating state of the droplet 228 of the ink with respect to the second substrate 210 can be measured. In this manner, it is possible to determine whether or not the application of the ink on the substrate 210 is appropriate by continuously measuring the contact angle [theta] and the application state of the ink droplet 228 with respect to the subsequently supplied substrate 210. [

On the other hand, when the contact angle [theta] of the droplet 228 of the measured ink and the application state deviate from the allowable tolerance range of the predetermined reference contact angle and the reference application state, it is judged that the ink application of the substrate 210 is inappropriate, If a subsequent operation (e.g., cleaning and re-use of the unsuitable substrate 210, or a new substrate 210 during cleaning of the unsuitable substrate 210, and re-use of the cleaned substrate 210 afterwards) Etc.) can be performed.

Further, even when the external condition is changed, such as when the ink being used is changed or when the surface state (flatness) of the substrate 210 is changed with the lapse of time, an embodiment of the present invention as described above The contact angle of the ink droplet and the application state of the ink in accordance with the new application conditions of the ink can be quickly changed in the field using the contact angle of the ink and the application state measurement system 270 according to the ink.

FIG. 2D is an exemplary view illustrating a specific region on a substrate to which the ink contact angle and the application state measuring system according to the embodiment of the present invention shown in FIG. 2A are applied.

Referring to FIG. 2D, the ink contact angle and coating state measurement system 270 according to an exemplary embodiment of the present invention may be configured to divide the substrate 210 into four regions A, B, C, and D, The contact angle and the application state of the at least one application ink with respect to the droplet 228 can be measured.

In addition, the substrate 210 can be divided into the inner region I and the outer region O to measure the contact angle and the application state of the ink with respect to the droplet 228. [ In this case, if the contact angle of the ink in the inner region I with respect to the droplet 228 and the application state frequently occur, the contact angle and the application state of the ink with respect to the droplet 228 in the inner region I It can be used as a data base of the control device 270 to subsequently check the contact angle of the ink and the application state thereof. Accordingly, for the subsequent substrate 210, only the contact angle and the application state of the ink in the inner region I with respect to the droplet 228 may be measured.

As described above, in the embodiment of FIG. 2 (d), dividing the substrate 210 into four regions A, B, C, and D or the inner region I and the outer region O is illustrative, It will be appreciated that the region partitioning of such substrate 210 may be arbitrarily selected by the user.

3 is a flowchart showing a method of measuring an ink contact angle and an application state according to an embodiment of the present invention.

Referring to FIG. 3 together with FIGS. 2A through 2D, an ink contact angle and application state measuring method 300 according to an exemplary embodiment of the present invention includes the steps of: a) Acquiring a first image (228a) of droplets (228) of ink to be ejected onto the substrate (210), and transmitting (310) the obtained first image (228a) to the control device (290); b) computing (320) a reference volume (RV) of the droplet (228) from the first image (228a) using the controller (290); c) applying (330) ink onto the substrate (210) to form a plurality of patterns (214) using a plurality of inkjet heads (220) of the inkjet printing apparatus (200); d) a plurality of second images 282a for droplets 228 of a plurality of inks applied on the substrate 210 at a plurality of locations on the substrate 210 using one or more second measurement cameras 282. Obtaining (340) and transmitting the obtained plurality of second images (282a) to the control device (290); And e) using the control device 290 to identify the respective application diameters 2D of the droplets 228 of the plurality of inks, wherein the respective respective application diameters 2D and the reference volume RV are identified. Calculating 350 a respective contact angle θ and application height H of the droplets 228 of the plurality of inks using the application state wherein the application state is the application diameter 2D and the application height. It is characterized by (H).

The method 300 for measuring an ink contact angle and an application state according to an embodiment of the present invention is characterized in that f) each of the contact angles? And the application state is within an allowable tolerance range of a predetermined reference contact angle and reference application state Further comprising determining that application of the ink of the substrate 210 is appropriate.

Also, the method 300 for measuring ink contact angle and coating state according to an embodiment of the present invention further comprises g) repeating steps c) through f) for the subsequently supplied substrate.

The method 300 for measuring an ink contact angle and an application state according to an embodiment of the present invention may further include the steps of: f1) determining whether the respective contact angles &thetas; and the applied state satisfy a predetermined reference contact angle and a reference application state Determining that the application of the ink on the substrate 210 is inappropriate and performing a subsequent operation with respect to the substrate 210 when the error is out of the allowable error range.

In addition, the method 300 for measuring the ink contact angle and the coating state according to an embodiment of the present invention may be modified such that the ink is changed to new ink, or the surface state of the substrate 210 is changed over time, , A new contact angle and a new application state can be measured by performing the steps a) to e) for the new ink or the new substrate.

The calculation of the contact angle? And the application height H in the ink contact angle and application state measuring method 300 according to an embodiment of the present invention is performed by a calculation program stored in advance in the control device 290 do.

As described above, in the present invention, the contact angle and the application state of the ink applied on the substrate are directly measured and confirmed in the field, and the constructed database for the specific region where the occurrence of defects frequently occurs is subsequently Can be used to confirm the contact angle and the application state of the ink, and can perform rapid subsequent operation in the field when the ink contact angle and the application state are inappropriate, and can change the ink used or change the surface state of the substrate with time It is possible to quickly change the contact angle and application state of the ink in the field so as to meet the new application conditions for the new ink or the new substrate, and the total process time (tact time) An effect that the occurrence possibility is remarkably reduced is achieved.

Various modifications may be made by those skilled in the art without departing from the spirit and scope of the invention as defined by the following claims. It is not. Accordingly, the scope of the present invention should not be limited by the above-described exemplary embodiments, but should be determined only in accordance with the following claims and their equivalents.

100, 200: inkjet printing apparatus 110, 210: substrate 110a: sample substrate
120, 220: inkjet heads 112, 172,
114, 214 pattern 121 piezoelectric element 122 heater
123: Piezoelectric drive device 124: Chamber / meniscus 126: Nozzle
128, 228: droplet 130.230: gantry 150, 250: ink storage device
152, 252: main conduits 152a, 152b, 152c, 152d, 152e:
154, 156a, 156b, 156c, 156d, 156e:
160, 260: frame 170, 270: contact angle and application state measuring system
174: ink drop device 180,182: measuring camera
190,290: Control device 228a, 228b: Image

Claims (16)

In a contact angle and ink application state measuring system of ink,
An ink jet head positioned on the substrate and discharging droplets of the ink onto the substrate;
A first measurement camera located on a side of the substrate and obtaining a first image of a droplet of the ink;
At least one second measurement camera that is stationary or movable at a plurality of locations on the substrate and that acquires a plurality of second images of droplets of a plurality of ink applied onto the substrate; And
A control device for receiving the first image and the plurality of second images from the first measurement camera and the at least one second measurement camera and measuring the contact angle and the application state of the liquid droplet of the ink,
Contact angle and coating state measurement system of the ink comprising a. The method of claim 1,
Wherein the at least one second measurement camera is implemented with a second measurement camera moving at the plurality of positions or with a plurality of second measurement cameras provided in a stationary state at the plurality of positions, State measurement system. The method of claim 1,
Wherein the controller calculates a reference volume of droplets of the ink from the first image,
The control device checks the coating diameter of the droplet from the second image and also calculates the contact angle and the coating height of the droplet from the coating diameter and the reference volume
The contact angle and application state measurement system of ink. The method of claim 3, wherein
Wherein the calculation of the contact angle and the application height is performed by a calculation program previously stored in the control device. In an inkjet printing apparatus,
A plurality of inkjet heads for supplying ink to form a plurality of patterns on a substrate;
A gantry on which the plurality of inkjet heads are mounted and movable on the substrate;
An ink storage device connected to the plurality of inkjet heads, respectively, for storing ink to be supplied to the plurality of inkjet heads;
A contact angle and ink application state measurement system for measuring the contact angle and the application state of the droplet of the ink; And
A control device for controlling the operation of each of the plurality of inkjet heads, the gantry,
Inkjet printing apparatus comprising a. 6. The method of claim 5,
The contact angle and the application state measurement system of the ink
One of the plurality of inkjet heads;
A first measurement camera located on a side of the substrate and obtaining a first image of a droplet of the ink;
At least one second measurement camera that is stationary or movable at a plurality of locations on the substrate and that acquires a plurality of second images of droplets of a plurality of ink applied onto the substrate; And
The control device
≪ / RTI >
The controller is configured to receive the first image and the plurality of second images from the first measuring camera and the at least one second measuring camera, respectively, to measure the contact angle and the coating state.
Inkjet printing apparatus. The method according to claim 6,
Wherein the at least one second measurement camera is implemented with a second measurement camera moving at the plurality of positions or with a plurality of second measurement cameras being provided in a stationary state at the plurality of positions. The method according to claim 6,
Wherein the controller calculates a reference volume of droplets of the ink from the first image,
The control device checks the coating diameter of the droplet from the second image and also calculates the contact angle and the coating height of the droplet from the coating diameter and the reference volume
Inkjet printing apparatus. The method of claim 8,
Wherein the calculation of the contact angle and the application height is performed by a calculation program previously stored in the control device. The method according to any one of claims 5 to 9,
When the ink is changed to a new ink or when the surface state of the substrate is changed over time so that a new substrate is used, a new ink or a new substrate for the new substrate is used by using the contact angle and application state measuring system of the ink. Inkjet printing apparatus for changing the contact angle and new application state. A method for measuring an ink contact angle and a coating state,
a) obtaining a first image of an ink droplet ejected onto a substrate by the inkjet head using a first measurement camera, and transmitting the obtained first image to a control device;
b) calculating a reference volume of the droplet from the first image using the control device;
c) applying ink onto the substrate to form a plurality of patterns using a plurality of inkjet heads of the inkjet printing apparatus;
d) acquiring a plurality of second images for a plurality of ink droplets deposited on the substrate at a plurality of locations on the substrate using one or more second measurement cameras, To a control device; And
e) determining a coating diameter of each droplet of the plurality of ink droplets using the control device, calculating a contact angle of each of the droplets of the plurality of ink droplets using the determined respective coating diameter and the reference volume, ≪ / RTI >
Including but not limited to:
The applied state is the coating diameter and the applied height
Method of measuring ink contact angle and application state. 12. The method of claim 11,
The method comprising the steps of: f) determining that application of the ink on the substrate is appropriate when each of the contact angles and the application state is within an allowable error range of a predetermined reference contact angle and a reference application state, Further comprising an ink contact angle and a method for measuring the applied state. 13. The method of claim 12,
Wherein the ink contact angle and the method for measuring the state of the ink further comprise: g) repeating the steps c) to f) for the subsequently supplied substrate. 13. The method of claim 12,
Wherein the ink contact angle and the state of application are measured by: f1) applying the ink on the substrate when the respective contact angles and the application state deviate from an allowable tolerance range of a predetermined reference contact angle and a reference application state in the step f) Further comprising determining that the substrate is not suitable and performing subsequent operations on the substrate. 15. The method according to any one of claims 11 to 14,
Wherein the ink contact angle and the method for measuring the state of coating are such that when the ink is changed to a new ink or the surface state of the substrate is changed over time and a new substrate is used, To (e)) to measure a new contact angle and a new application state. 15. The method according to any one of claims 11 to 14,
Wherein the calculation of the contact angle and the application height is performed by a calculation program previously stored in the control device.

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