Display device with iCVD buffer layer in bank trench
A display device according to an example embodiment of the present disclosure includes a substrate having a plurality of sub-pixels defined thereon, a bank disposed between the plurality of sub-pixels, at least one trench pattern disposed between the plurality of sub-pixels and from which a thickness of an upper surface of the bank is partially removed, a buffer layer on the bank, the buffer layer being deposited to cover an inner surface of the trench pattern by an initiated chemical vapor deposition (iCVD) method and an encapsulation layer disposed on the buffer layer. Therefore, it is possible to improve reliability by preventing film formation defects of the encapsulation layer in the trench, and to improve display quality by preventing display quality defects such as light and dark spots and bright spots.
1 . A display device, comprising:
a substrate having a plurality of sub-pixels defined thereon;
a bank disposed between the plurality of sub-pixels;
at least one trench pattern disposed between the plurality of sub-pixels and from which a thickness of an upper surface of the bank is partially removed;
a buffer layer on the bank, the buffer layer being deposited to cover an inner surface of the trench pattern by an initiated chemical vapor deposition (iCVD) method; and
an encapsulation layer disposed on the buffer layer,
wherein each trench pattern extends along and surrounds at least two sides of a corresponding sub-pixel.
2 . The display device of claim 1 , further comprising:
an anode disposed in each of the plurality of sub-pixels;
an organic layer disposed on the anode; and
a cathode disposed on the organic layer,
wherein the organic layer and the cathode are disconnected in the trench pattern between the sub-pixels adjacent to each other.
3 . The display device of claim 1 , wherein the buffer layer is configured by copolymerization of an initiator and at least two acrylic monomers.
4 . The display device of claim 3 , wherein:
the initiator includes tert-butyl peroxide (TBPO), and
the monomers include a monomer 1 of glycidyl methacrylate (GMA) and a monomer 2 of 2-hydroxyethyl acrylic acid (HEA).
5 . The display device of claim 4 , wherein:
the fraction of the monomer 1 and the monomer 2 is set to 1.6:1 to 2:1; and
the buffer layer is conformally deposited to cover an inner surface of the trench pattern along an inner shape of the trench pattern.
6 . The display device of claim 4 , wherein;
the fraction of the monomer 1 and the monomer 2 is set to 3:1 to 4:1; and
the buffer layer is flowably deposited to cover an upper portion of the trench pattern, including an inside of the trench pattern.
7 . The display device of claim 1 , wherein when a foreign material is disposed on the bank, the buffer layer is deposited to completely cover an inversely tapered portion of the foreign material without a seam.
8 . The display device of claim 1 , wherein the encapsulation layer includes:
a primary protective layer disposed on the buffer layer;
an organic layer disposed on the primary protective layer; and
a secondary protective layer disposed on the organic layer, wherein the buffer layer is disposed to extend to a non-active area of the substrate.
9 . The display device of claim 8 , further comprising:
a plurality of dam portions disposed in the non-active area, wherein the organic layer is disposed to extend to a front of the plurality of dam portions.
10 . The display device of claim 9 , wherein the buffer layer is deposited on the plurality of dam portions along bending of the plurality of dam portions.
11 . The display device of claim 8 , wherein;
the organic layer is deposited on the primary protective layer by the iCVD method; and
the organic layer extends to a portion of the non-active area.
12 . The display device of claim 11 , wherein a dam portion does not exist outside the organic layer extending to the portion of the non-active area.
13 . The display device of claim 1 , further comprising:
at least one spacer disposed on the bank between the plurality of sub-pixels.
14 . The display device of claim 13 , wherein the buffer layer is deposited on the spacer along a bending of the spacer.
15 . The display device of claim 13 , wherein;
the spacer has an inversely tapered shape; and
the buffer layer is deposited to completely cover an inversely tapered portion of the spacer so that a seam is not formed.
16 . The display device of claim 15 , wherein the primary protective layer deposited on the buffer layer has a seam in the inversely tapered portion of the spacer.
17 . The display device of claim 15 , wherein when the buffer layer is flowably deposited, the primary protective layer is deposited on the buffer layer so as not to have a seam in the inversely tapered portion of the spacer.
18 . A display device, comprising:
a plurality of sub-pixels disposed above a substrate;
a bank disposed above the substrate;
at least one trench pattern formed in the bank and between the plurality of sub-pixels;
a buffer layer formed within the at least one trench pattern via application of an initiated chemical vapor deposition (iCVD) method; and
an encapsulation layer disposed above the buffer layer,
wherein each trench pattern extends along and surrounds at least two sides of a corresponding sub-pixel.
19 . The display device of claim 18 , wherein the buffer layer is conformally deposited within the at least one trench pattern.
20 . The display device of claim 18 , wherein: the buffer layer covers an inner surface of the at least one trench pattern.
21 . The display device of claim 18 , wherein: the at least one trench pattern corresponds with a partial removal of a portion of the bank.
22 . The display device of claim 18 , further comprising:
an organic layer disposed within the at least one trench pattern, the buffer layer is disposed above the organic layer.
23 . The display device of claim 18 , further comprising:
an organic layer disposed above the bank, a first portion of the organic layer formed within the at least one trench pattern is disconnected from a second portion of the organic layer formed on an upper surface of the bank.
24 . The display device of claim 18 , further comprising:
an anode disposed above the substrate;
an organic layer disposed above the anode; and
a cathode layer disposed above the organic layer, the buffer layer disposed above the cathode layer, a first portion of the organic layer formed within the at least one trench pattern is disconnected from a second portion of the organic layer formed above the anode, a first portion of the cathode layer formed within the at least one trench pattern is disconnected from a second portion of the cathode layer formed above the anode.