SYSTEMS AND METHODS FOR DRYING PATTERNED OLED FORMULATIONS
A drying chamber for drying a substrate patterned with display areas wetted by OLED materials dissolved or suspended in a volatile carrier liquid and separated from one another by dry boundary regions. A mask adjusts drying rate of the carrier liquid during vacuum extraction using vapor-transmissive areas opposite the wet areas and vapor-barrier regions opposite the dry boundary regions, or by confining the wet areas collectively in a chamber volume small enough to quickly saturate with the carrier liquid before vacuum extraction.
1 . A drying chamber comprising:
a substrate support disposed within an enclosure, the substrate support having a support surface;
a mask having vapor-transmissive areas and vapor-barrier regions disposed across the support surface of the substrate support within the enclosure at an adjustable distance from the support surface;
a gas source coupled to the enclosure; and
a vacuum source coupled to the enclosure.
2 . The drying chamber of claim 1 , wherein the mask has mask supports that extend through the enclosure.
3 . The drying chamber of claim 2 , wherein the mask supports are located on two opposite sides of the mask.
4 . The drying chamber of claim 1 , further comprising a gas-distribution element between the mask and the vacuum source.
5 . The drying chamber of claim 4 , further comprising a peripheral vapor barrier encompassing a gap between the mask and the gas-distribution element.
6 . The drying chamber of claim 4 , wherein the gas source is coupled to the enclosure at a location that provides a gas flow outside the vapor barrier.
7 . The drying chamber of claim 1 , wherein the mask includes a wall extending from a proximate surface of the mask toward the support surface.
8 . The drying chamber of claim 1 , wherein the substrate support includes temperature-control elements.
9 . The drying chamber of claim 1 , wherein the mask comprises a rigid material disposed over and spaced apart from the substrate.
10 . The drying chamber of claim 1 , wherein each vapor-transmissive area has a single opening, a plurality of openings, a mesh, a screen, or a porous material.
11 . A method for drying a substrate having wet areas wet with a carrier liquid separated by dry boundary regions, the method comprising:
orienting a mask relative to the substrate, the mask having vapor-transmissive areas and vapor-barrier regions;
drawing the carrier liquid from the wet areas of the substrate through the vapor-transmissive areas of the mask.
12 . The method of claim 11 , wherein orienting a mask relative to the substrate positions the vapor-transmissive areas opposite the wet areas and the vapor-barrier regions opposite the dry boundary regions.
13 . The method of claim 12 , further comprising setting a gap between the substrate and the mask.
14 . The method of claim 12 , the drawing passing the carrier liquid through a perforated gas-distribution element.
15 . The method of claim 14 , wherein each of the wet areas are of a first shape and each of the vapor-transmissive areas extend over a similar second shape, the method further comprising aligning the wet areas relative to the vapor-transmissive areas.
16 . A drying chamber comprising:
a substrate support to support a substrate having wet areas separated by dry boundary regions, the wet areas including a volatile carrier liquid that exhibits a carrier-liquid vapor pressure;
a gas-distribution mechanism defining a process space of a process-space volume over the substrate, wherein the process-space volume approaches saturation of a vapor of the volatile carrier liquid within five minutes; and
a vacuum source to draw the vapor of the volatile carrier liquid from the process space.
17 . The drying chamber of claim 16 , further comprising an actuator connected to one of the substrate support and the gas-distribution mechanism to load and unload the substrate.
18 . The drying chamber of claim 16 , further comprising a secondary process space encompassing the substrate support and the gas-distribution mechanism.
19 . The drying chamber of claim 18 , further comprising a gas source providing air to the secondary process space.