510 may include an area camera or a line scan camera. The camera 510 may be movable on the gantry 320 in the second horizontal direction (Y direction) by the camera actuator 520.

The camera actuator 520 may include a first actuator for moving the camera 510 in the second horizontal direction (Y direction), and a second actuator for moving the camera 510 in the vertical direction (Z direction). The camera 510 may be configured to move in the second horizontal direction (Y direction) and the vertical direction (Z direction) on the gantry 320 by the first and second actuators. Alternatively, the camera actuator 520 may move the camera 510 independently of the inkjet head 310.

The controller 530 may obtain position coordinates for the dots comprising the test pattern from the image taken by the camera 510. The controller 530 may compare the position coordinates to a preset reference coordinate. The controller 530 may compensate for the jet position of the chemical solution by comparing the position coordinates with the preset reference coordinates. That is, if the controller 530 compares the position coordinates with the preset reference coordinates and a difference occurs, the controller 530 may determine that the impingement point of the chemical solution is abnormal, and may calculate a correction amount of the jet position of the chemical solution based on the difference.

In the following, a substrate processing method using the substrate processing apparatus will be described.

FIG. 3 is a flow diagram illustrating the substrate processing method according to exemplary embodiments. FIG. 4 is a diagram illustrating a process for obtaining first and second calibration values by calibrating second and third reference jet values, respectively, based on a first reference jet value.

The substrate processing method according to exemplary embodiments may be implemented as a computer program reflecting the substrate processing logic described herein. The substrate processing method may be performed by the processor of the main control unit 70 executing the computer program.

Referring to FIGS. 3 and 4, a first test film TS1 having first to third reference areas RA1, RA2, and RA3 may be provided (S110).

In exemplary embodiments, the substrate processing method may be to jet the chemical solution onto the substrate using an inkjet printing apparatus. The inkjet printing apparatus may jet the chemical solution onto the substrate via a plurality of nozzles. For example, the substrate may include a display substrate or a film substrate.

The first test film (reference test film) TS1 may be a substrate for testing the reliability of the inkjet printing apparatus. The inkjet printing apparatus may jet the chemical solution onto the first test film TS1 through the plurality of nozzles. The jet direction of each of the plurality of nozzles may be determined from the chemical solution jetted onto the first test film TS1. The jet direction of each of the plurality of nozzles may vary during the repeated process.

The first test film TS1 may have a plurality of divided reference areas. The first test film TS1 may have first and second reference areas RA1, and RA2 that are adjacent to each other. The first test film TS1 may further have the third reference area RA3 adjacent to the second reference area RA2.

The substrate processing method may perform a plurality of tests by dividing the first test film TS1 into the plurality of reference areas. The substrate processing method may jet the chemical solution onto the first to third reference areas RA1, RA2, and RA3 of the first test film TS1 to determine the impingement points. The impingement points may be used to calibrate the jet direction of each of the plurality of nozzles.

Since the substrate processing method performs the tests by dividing the first test film TS1 into the plurality of reference areas, the efficiency of the first test film TS1 can be maximized, thereby reducing production costs. For example, the first test film TS1 may include a nozzle jetting inspection film (NJI film).

Each of the first to third reference areas RA1, RA2, and RA3 may have a first width W1. The first width W1 may be the minimum width over which the first test film TS1 can be divided into the plurality of reference areas to perform the test. The first width W1 of each of the first to third reference areas RA1, RA2, and RA3 may be within a range of 5 mm to 15 mm.

Subsequently, first to third reference jet values (or, reference discharge values) RDV1, RDV2, and RDV3 may be obtained from first to third reference test patterns RTP1, RTP2, and RTP3 formed by jetting the chemical solution through the plurality of nozzles onto the first to third reference areas RA1, RA2, and RA3 of the first test film TS1, respectively (S120).

In exemplary embodiments, the chemical solution may be jetted onto the first to third reference areas RA1, RA2, and RA3 of the first test film TS1 to form the first to third reference test patterns RTP1, RTP2, and RTP3, respectively. The first to third reference test patterns RTP1, RTP2, and RTP3 may have the impingement points of the chemical solution jetted through the plurality of nozzles.

The first reference test pattern RTP1 may be a test pattern that is referred to in order to keep the jet direction of each of the plurality of nozzles constant during the repeated process. As will be described later, the first reference test pattern RTP1 may be the reference for the first to third test patterns TP1, TP2, and TP3 of a second test film TS2 used to jet the chemical solution onto the first and second substrates.

The first to third reference jet values RDV1, RDV2, and RDV3 may be obtained by calculating coordinates from the impingement points of each of the first to third reference test patterns RTP1, RTP2, and RTP3. The first to third reference jet values RDV1, RDV2, and RDV3 may have errors caused by differences in the location, environment, etc. of the first to third reference areas RA1, RA2, and RA3. As will be described later, the first to third reference jet values RDV1, RDV2, and RDV3 may be reference coordinate values for compensating for the above errors caused by repeated printing processes.

Each of the first to third reference test patterns RTP1, RTP2, and RTP3 may be scanned via the area camera or the line scan camera. The first to third reference test patterns RTP1, RTP2, and RTP3 may be acquired by scanning the first to third reference areas RA1, RA2, and RA3, respectively, in their entirety through the area camera. The first to third reference test patterns RTP1, RTP2, and RTP3 may be acquired by the line scan camera moving over the first to third reference areas RA1, RA2, and RA3.

For example, printing processes for different plurality of display substrates may be performed in between the processes of jetting the chemical solution onto the first to third reference areas RA1, RA2, and RA3 of the first test film TS1.

Then, first and second calibration values OV1, and OV2 may be obtained by calibrating the second and third reference jet values RDV2, and RDV3, respectively, based on the first reference jet value RDV1 (S130).

In exemplary embodiments, the first calibration value (first offset value) OV1 may be obtained by calibrating the second reference jet value RDV2 based on the first reference jet value RDV1. The first calibration value OV1 may be the difference between the first reference jet value RDV1 and the second reference jet value RDV2. The first calibration value OV1 may be an offset value that occurs between the first reference jet value RDV1 and the second reference jet value RDV2. The first calibration value OV1 may be an offset value to compensate for the error between the first reference jet value RDV1 obtained from the first reference area RA1 and the second reference jet value RDV2 obtained from the second reference area RA2.

The second calibration value (second offset value) OV2 may be obtained by calibrating the third reference jet value RDV3 based on the first reference jet value RDV1. The second calibration value OV2 may be the difference between the first reference jet value RDV1 and the third reference jet value RDV3. The second calibration value OV2 may be an offset value between the first reference jet value RDV1 and the third reference jet value RDV3. The second calibration value OV2 may be an offset value to compensate for the error between the first reference jet value RDV1 obtained from the first reference area RA1 and the third reference jet value RDV3 obtained from the third reference area RA3.

FIG. 5 is a diagram illustrating the process of calibrating the first to third jet values based on the first reference jet value and the first and second calibration values.

Referring now to FIGS. 3 to 5, the second test film TS2 having first to third areas A1, A2, and A3 may be provided (S210).

In exemplary embodiments, the jet direction of each of the plurality of nozzles may be verified by the jet of the chemical solution onto the second test film TS2. The jet direction of each of the plurality of nozzles may vary over the course of a repeated process.

The second test film TS2 may have a plurality of segmented areas. The second test film TS2 may have first and second areas A1, and A2 that are adjacent to each other. The first test film TS1 may further have a third area A3 adjacent to the second area A2.

The first to third areas A1, A2, and A3 of the second test film TS2 may be areas corresponding to the first to third reference areas RA1, RA2, and RA3 of the first test film TS1, respectively. The first test film TS1 and the second test film TS2 may be the same type of substrate for testing the reliability of the inkjet printing apparatus.

In contrast, the second test film TS2 may be a single film substrate identical to the first test film TS1. In this case, the first and second areas A1, and A2 of the second test film TS2 may be in the same plane as the first and second reference areas RA1, and RA2 of the first test film TS1.

The test film and the reference test film are the same single film substrate, and the first and second areas and the first and second reference areas RA1, and RA2 may be coplanar with each other.

The substrate processing method may include dividing the second test film TS2 into a plurality of areas to perform a plurality of tests. The substrate processing method may determine the impingement points by jetting the chemical solution onto the first to third areas A1, A2, and A3 of the second test film TS2. The impingement points may be used to calibrate the jet direction of each of the plurality of nozzles.

Since the substrate processing method partitions the second test film TS2 into a plurality of areas to perform the tests, the efficiency of the second test film TS2 can be maximized, thereby reducing production costs. For example, the second test film TS2 may include a nozzle jetting inspection film (NJI film).

Each of the first to third areas A1, A2, A3 may have a second width W2. The second width W2 may be a minimum width that allows the second test film TS2 to be divided into the plurality of areas to perform the test. The second width W2 of each of the first to third areas A1, A2, and A3 may be within a range of 5 mm to 15 mm.

Subsequently, a first jet value DV1 can be obtained from the first test pattern RP1 formed by jetting the chemical solution through the plurality of nozzles onto the first area A1 of the second test film TS2 (S220), and the chemical solution may be jetted onto the first substrate by calibrating the jet direction of each of the plurality of nozzles based on the first jet value DV1 (S230).

In exemplary embodiments, a first test pattern TP1 may be formed by jetting the chemical solution onto the first area A1 of the second test film TS2. The first test pattern TP1 may have the impingement points of the chemical solution jetted through the plurality of nozzles.

The first test pattern TP1 may be scanned via the area camera or the line scan camera. The first jet value DV1 may be obtained by calculating coordinates from the impingement points of the first test pattern TP1. The first test pattern TP1 may be a test pattern corresponding to the first reference test pattern RTP1.

In exemplary embodiments, the first substrate may include a display substrate or a film substrate. Since the substrate processing method jets the chemical solution onto the first substrate based on the first jet value DV1, the jet angle of the plurality of nozzles may be kept constant.

The first jet value DV1 may be calibrated based on the first reference jet value RDV1. The first jet value DV1 may have a reference jet coordinate RDC calibrated based on the first reference jet value RDV1.

Alternatively, since the first area A1 of the first test film TS1 and a second area A2 of the second test film TS2 correspond to each other, the first jet value DV1 may have the same pattern as the first reference jet value RDV1. Since the first jet value DV1 has the same pattern as the first reference jet value RDV1, the first jet value DV1 may be used to jet the chemical solution onto the first substrate without calibration.

Next, a second jet value may be obtained from a second test pattern TP2 formed by jetting the chemical solution through the plurality of nozzles onto the second area A2 of the second test film TS2 (S240).

In exemplary embodiments, the second test pattern TP2 may be formed by jetting the chemical solution onto the second area A