Substrate processing method and substrate processing system using the same
A substrate processing method includes determining a first impact of an ink droplet ejected toward a substrate moving at a first speed, determining a second impact of an ink droplet ejected toward the substrate moving at a second speed, determining a reference ejection speed based on the first impact and the second impact, determining a plurality of third impacts of a plurality of ink droplets respectively ejected from a plurality of nozzles toward the substrate moving at a third speed, determining an ink ejection speed of each of the plurality of nozzles based on the first impact and the plurality of third impacts, and comparing the ink ejection speeds of the plurality of nozzles with the reference ejection speed and determining whether ink ejection performance of the plurality of nozzles is abnormal.
1 . A substrate processing method comprising:
determining a first impact of an ink droplet ejected toward a substrate moving at a first speed;
determining a second impact of an ink droplet ejected toward the substrate moving at a second speed;
determining a reference ejection speed based on the first impact and the second impact;
determining a plurality of third impacts of a plurality of ink droplets respectively ejected from a plurality of nozzles toward the substrate moving at a third speed;
determining an ink ejection speed of each of the plurality of nozzles based on the first impact and the plurality of third impacts; and
comparing the ink ejection speeds of the plurality of nozzles with the reference ejection speed and determining whether ink ejection performance of the plurality of nozzles is abnormal.
2 . The substrate processing method of claim 1 , wherein the plurality of ink droplets respectively ejected from the plurality of nozzles are ejected simultaneously.
3 . The substrate processing method of claim 1 , wherein, during the determining of the ink ejection speed of each of the plurality of nozzles, the ink ejection speeds of the plurality of nozzles are simultaneously determined.
4 . The substrate processing method of claim 1 , wherein the first impact and the second impact are generated by ink droplets ejected from a first nozzle toward the substrate, and
during the determining of the reference ejection speed using the first impact and the second impact,
the first speed, the second speed, a distance from the first nozzle to the substrate, and a distance between the first impact and the second impact are used.
5 . The substrate processing method of claim 4 , wherein, during the determining of the reference ejection speed, Equation (1) below is used
Reference
ejection
speed
=
(
First
speed
-
Second
speed
)
×
Distance
from
first
nozzle
to
substrate
Distance
between
first
impact
and
second
impact
.
(
1
)
6 . The substrate processing method of claim 1 , wherein the substrate moves in a first direction parallel to an upper surface of the substrate, and
the ink droplets are ejected in a second direction perpendicular to the upper surface of the substrate.
7 . The substrate processing method of claim 1 , wherein, during the determining of whether the ink ejection performance of the plurality of nozzles is abnormal,
at least one of a median value and a standard deviation of the ink ejection speeds of the plurality of nozzles is used.
8 . The substrate processing method of claim 1 , further comprising, after the determining of whether the ink ejection performance of the plurality of nozzles is abnormal,
correcting the ink ejection performance based on abnormalities in the ink ejection performance.
9 . A substrate processing system comprising:
a nozzle head unit comprising a plurality of nozzles that eject ink droplets on a substrate using an inkjet method; and
an inspection device determining an ink ejection speed of each of the plurality of nozzles based on impacts of ink droplets ejected from the nozzle head unit to the substrate, wherein the inspection device;
determines a first impact of an ink droplet ejected toward a substrate moving at a first speed;
determines a second impact of an ink droplet ejected toward the substrate moving at a second speed;
determines a reference ejection speed based on the first impact and the second impact;
determines a plurality of third impacts of a plurality of ink droplets respectively ejected from a plurality of nozzles toward the substrate moving at a third speed;
determines an ink ejection speed of each of the plurality of nozzles based on the first impact and the plurality of third impacts; and
compares the ink ejection speeds of the plurality of nozzles with the reference ejection speed and determining whether ink ejection performance of the plurality of nozzles is abnormal,
wherein the inspection device, after the determining of whether the ink ejection performance of the plurality of nozzles is abnormal, the inspection device corrects the ink ejection performance by changing voltages applied to each of the plurality of nozzles.
10 . The substrate processing system of claim 9 , wherein the inspection device simultaneously inspects the impacts of the ink droplets simultaneously ejected from the plurality of nozzles.
11 . The substrate processing system of claim 9 , wherein, during the determining of the ink ejection speeds, Equation (2) below is used
Ink
ejection
speed
=
(
First
speed
-
Second
speed
)
×
Distance
from
each
of
plurality
of
nozzles
to
substrate
Distance
between
first
impact
and
second
impact
.
(
2
)