Display apparatus having protective layer on the pad unit and method of fabricating the same

1. A display apparatus, comprising:

a substrate;

a pad unit on the substrate, the pad unit including:

a pad electrode on the substrate; and

a flexible printed circuit board on the pad electrode, the flexible printed circuit board being electrically connected to the pad electrode;

a display panel on the substrate;

an encapsulation layer covering the display panel and a portion of the pad electrode; and

a protective layer on the pad unit, the protective layer covering a region of the pad electrode and at least a portion of a region of the flexible printed circuit board, the protective layer having an elastic coefficient ranging from 10 MPa to 200 GPa, the protective layer including:

an organic layer on the pad unit, and

a first pattern on the organic layer, the organic layer being interposed between the pad unit and the first pattern,

wherein:

the organic layer includes an organic material that includes at least one of a cyclic olefin copolymer (COC), a poly(methyl methacrylate) (PMMA), a polycarbonate (PC), a cyclo olefin polymer (COP), a liquid crystal polymer (LCP), a polydimethyl siloxane (PDMS), a polyamide (PA), a polyethylene (PE), a polyimide (PI), a polypropylene (PP), a polyphenylene ether (PPE), a polystyrene (PS), polyoxymethylene (POM), a polyetheretherketone (PEEK), a polyethylene terephthalate (PET), a polytetrafluoroethylene (PTFE), a polyvinylchloride (PVC), a polyvinylidene fluoride (PVDF), a polybutylene terephthalate (PBT), a fluorinated ethylene propylene (FEP), or a tetrafluoroethylene (PFA), and

the first pattern includes an organic material having an elastic coefficient less than the elastic coefficient of the organic material of the organic layer.

2. The display apparatus as claimed in claim 1 , wherein the protective layer further includes an inorganic material or a metal material.

3. The display apparatus as claimed in claim 2 , wherein the inorganic material is a carbon film, silicon carbide, or an oxide-based material.

4. The display apparatus as claimed in claim 2 , wherein the metal material is tungsten or tungsten carbide.

5. The display apparatus as claimed in claim 1 , wherein the protective layer includes an organic layer including an organic material, a metal layer on the organic layer, and an inorganic layer on the metal layer.

6. The display apparatus as claimed in claim 1 , wherein the protective layer includes at least one organic layer, at least one metal layer, and at least one inorganic layer that are alternately stacked.

7. The display apparatus as claimed in claim 1 , wherein the first pattern includes a cyclic olefin copolymer (COC), a poly(methyl methacrylate) (PMMA), a polycarbonate (PC), a cyclo olefin polymer (COP), a liquid crystal polymer (LCP), a polydimethyl siloxane (PDMS), a polyamide (PA), a polyethylene (PE), a polyimide (PI), a polypropylene (PP), a polyphenylene ether (PPE), a polystyrene (PS), polyoxymethylene (POM), a polyetheretherketone (PEEK), a polyethylene terephthalate (PET), a polytetrafluoroethylene (PTFE), a polyvinylchloride (PVC), a polyvinylidene fluoride (PVDF), a polybutylene terephthalate (PBT), a fluorinated ethylene propylene (FEP), a tetrafluoroethylene (PFA), or a mixture thereof.

8. The display apparatus as claimed in claim 1 , wherein the first pattern has a trapezoidal or triangular shape in section.

9. The display apparatus as claimed in claim 1 , further comprising a planarization layer on the organic layer, the planarization layer covering the first pattern.

10. The display apparatus as claimed in claim 9 , wherein the planarization layer includes a liquid phase resin, the liquid phase resin having an elastic coefficient less than an elastic coefficient of the first pattern.

11. The display apparatus as claimed in claim 9 , further comprising a second pattern on the protective layer, wherein the second pattern includes a cyclic olefin copolymer (COC), a poly(methyl methacrylate) (PMMA), a polycarbonate (PC), cyclo olefin polymer (COP), a liquid crystal polymer (LCP), a polydimethyl siloxane (PDMS), a polyamide (PA), a polyethylene (PE), a polyimide (PI), a polypropylene (PP), a polyphenylene ether (PPE), a polystyrene (PS), a polyoxymethylene (POM), a polyetheretherketone (PEEK), a polyethylene terephthalate (PET), a polytetrafluoroethylene (PTFE), a polyvinylchloride (PVC), a polyvinylidene fluoride (PVDF), a polybutylene terephthalate (PBT), a fluorinated ethylene propylene (FEP), a tetrafluoroethylene (PFA), or a mixture thereof.

12. The display apparatus as claimed in claim 1 , wherein the display panel includes a plurality of organic light-emitting display devices (OLEDs) spaced apart from each other in a display area of the display panel.

13. A method of fabricating a display device, the method comprising:

providing a substrate:

forming a display panel on a display region of the substrate;

forming a pad unit on the substrate, the pad unit including:

a pad electrode on the substrate; and

a flexible printed circuit board on the pad electrode, the flexible printed circuit board being electrically connected to the pad electrode;

forming an encapsulation layer covering the display panel and part of the pad electrode; and

forming a protective layer on the pad unit, the protective layer covering a region of the pad electrode and a region of the flexible printed circuit board, wherein the protective layer has an elastic coefficient ranging from about 10 MPa to about 200 GPa, the protective layer including:

an organic layer on the pad unit, and

a first pattern on the organic layer, the organic layer being interposed between the pad unit and the first pattern, wherein:

the organic layer includes an organic material that includes at least one of a cyclic olefin copolymer (COC), a poly(methyl methacrylate) (PMMA), a polycarbonate (PC), a cyclo olefin polymer (COP), a liquid crystal polymer (TCP), a polydimethyl siloxane (PDMS), a polyamide (PA), a polyethylene (PE), a polyimide (PI), a polypropylene (PP), a polyphenylene ether (PPE), a polystyrene (PS), polyoxymethylene (POM), a polyetheretherketone (PEEK), a polyethylene terephthalate (PET), a polytetrafluoroethylene (PTFE), a polyvinylchloride (PVC), a polyvinylidene fluoride (PVDF), a polybutylene terephthalate (PBT), a fluorinated ethylene propylene (FEP), or a tetrafluoroethylene (PFA), and

the first pattern includes an organic material having an elastic coefficient less than the elastic coefficient of the organic material of the organic layer.

14. The method as claimed in claim 13 , wherein forming the protective layer includes using an adhesive on the pad electrode.

15. The method as claimed in claim 13 , wherein forming the protective layer includes using a liquid phase resin on the pad electrode.

16. The method as claimed in claim 13 , wherein the encapsulation layer includes an organic material, an inorganic material, or a metal material.