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EP-3614431-B1 - FLEXIBLE DISPLAY PANEL AND MANUFACTURING METHOD THEREFOR

EP3614431B1EP 3614431 B1EP3614431 B1EP 3614431B1EP-3614431-B1

Inventors

  • YUAN, BO
  • HUANG, Genmao
  • CUI, ZHIYUAN
  • HU, KUN
  • XU, LIN
  • LI, BO

Dates

Publication Date
20260506
Application Date
20180524

Claims (7)

  1. A flexible display panel (100), characterized by , comprising: a flexible substrate (101); a buffer layer (102) formed on the flexible substrate (101), the buffer layer (102) comprising a first portion and a second portion; a metal layer (103) at least formed on the second portion of the buffer layer (102); and a planarization layer (105), and a passivation layer (104) formed between the planarization layer (105) and the metal layer (103), wherein the passivation layer (104) and the planarization layer (105) are made of organic materials, wherein the flexible display panel (100) comprises a display area (1) and a bending area (3) in a lateral direction, the first portion of the buffer layer (102) corresponds to the display area (1), the second portion of the buffer layer (102) corresponds to the bending area (3), and a thickness of the second portion of the buffer layer (102) is less than a thickness of the first portion, wherein the first portion of the buffer layer (102) comprises a first SIO x layer (106), a SIN X layer (107) and a second SIO x layer (108) successively disposed, the first SIO x layer (106) is disposed on the flexible substrate (101), and the second portion comprises a first SIO x layer (109), wherein the second portion of the buffer layer (102) does not comprise the SIN x layer (107) and the second SIO x layer (108), wherein a thickness of the first SIO X layer (109) of the second portion is less than a thickness of the first SIO X layer (106) of the first portion.
  2. The flexible display panel (100) according to claim 1, wherein the flexible display panel (100) further comprises a transition area (2) in the lateral direction, the transition area (2) is located between the display area (1) and the bending area (3), the buffer layer (102) further comprises a third portion corresponding to the transition area (2), and the third portion gradually decreases in width in a direction from the flexible substrate (101) toward the metal layer (103).
  3. The flexible display panel (100) according to any one of the previous claims, wherein the thickness of the first portion is from 300 nm to 1400 nm, and the thickness of the second portion is from 10 nm to 100 nm.
  4. The flexible display panel (100) according to any one of the previous claims, wherein the thickness of the second portion is from 10 nm to 30 nm.
  5. A manufacturing method, for manufacturing a flexible display panel comprising a display area and a bending area in a lateral direction, characterized by , comprising: providing a flexible substrate; forming (301) a buffer layer on the flexible substrate; defining a portion of the buffer layer corresponding to the display area as a first portion, etching (302) a portion of the buffer layer corresponding to the bending area to obtain a second portion, and making a thickness of the second portion to be less than a thickness of the first portion; forming (303) a metal layer at least on the second portion of the buffer layer; and forming a passivation layer on the metal layer, and forming a planarization layer on the passivation layer, wherein the passivation layer and the planarization layer are made of organic materials, wherein the forming (301) a buffer layer on the flexible substrate comprises: forming (402) a first SIO X layer, a SIN X layer and a second SIO X layer successively on the flexible substrate, wherein the etching (302) a portion of the buffer layer corresponding to the bending area to obtain a second portion comprises: etching (403) the second SIO X layer and the SIN X layer of the buffer layer corresponding to the bending area to expose the first SIO X layer of the second portion, wherein after the etching (403) the second SIO x layer and the SIN x layer of the buffer layer corresponding to the bending area to expose the first SIO X layer of the second portion, the manufacturing method further comprises: further etching (404) the first SIO x layer of the second portion, till a thickness of the first SIO x layer of the second portion is less than a thickness of the first SIO X layer of the first portion.
  6. The manufacturing method according to claim 5, wherein the flexible display panel further comprises a transition area in the lateral direction, the transition area is located between the display area and the bending area, the manufacturing method further comprises: etching (405) a portion of the buffer layer corresponding to the transition area to obtain a third portion, wherein the third portion gradually decreases in width in a direction from the flexible substrate toward the metal layer.
  7. The manufacturing method according to claim 5 or 6, wherein the thickness of the second portion is from 10 nm to 30 nm.

Description

TECHNICAL FIELD The present application relates to the field of display technologies, and in particularly to a flexible display panel and a manufacturing method thereof. BACKGROUND A flexible foldable display, such as an Organic Light Emitting Display (OLED), may provide users with new visual experience. However, after repeated bending of the display, a problem of metal lines breakage is easily generated, thereby affecting displaying. A current solution is to protect the metal lines by adopting an insulating layer/metal layer /insulating layer/planarization layer structure. However, the Young's modulus of the insulating layer is large, and a breakage is easily generated when bending, resulting in the metal lines breakage. Patent application document No. US2015/268775 A1 discloses an electronic device that includes a flexible display with portions that can be bent. The display may include an array of display pixels in an active area. Contact pads may be formed in an inactive area of the display. Display circuitry in the active area may exhibit a given stack height, whereas display circuitry in the inactive area may exhibit a stack height that is less than the given stack height. In particular, the contact pads may be formed directly on a multi-buffer layer that sits directly on a flexible display substrate. Patent application document No. WO2014/126403 A1 discloses a flexible display that includes a flexible substrate having a display area and a bending area adjacent to the display area. A wire electrically connected to a display unit in the display area extends into the bending area of the flexible substrate and has a trace pattern arranged in an orthogonal direction relative to a boundary between the display area and the bending area. The wire is covered by an upper insulating pattern, which has substantially the same trace pattern as the wire thereunder. Patent application document No. CN 106601133 A and the family member US2020/0243574 A1 disclose a flexible display panel that includes a flexible substrate and an inorganic insulating layer(s) and an organic insulating layer on the flexible substrate. The inorganic insulating layer(s) is provided with a recess in a region to be bent of the flexible display panel. The organic insulating layer at least covers a surface of the recess, and the flexibility of the organic insulating layer is greater than that of the inorganic insulating layer(s). Patent application document KR 20140099164A and the family member US2014/217373A1 disclose a flexible organic light emitting display device that includes a flexible substrate, a buffer layer and wires. The buffer layer formed on the non-display area of the flexible substrate may be thinner than the buffer layer formed on the display area of the flexible substrate. Patent application document EP 3291321A1 discloses a flexible display, and the flexible display includes: a base layer which including a first portion having a first surface on which an organic light emitting element is disposed and a second portion extending from the outside of the first portion and bent toward a second surface opposing to the first surface; a protective film covering at least a part of the second portion to suppress permeation of moisture; a polarization layer disposed on the organic light emitting element of the first portion without having a barrier film between the polarization layer and the base layer; and a resin filled between the polarization layer and the protective film. SUMMARY Embodiments of the present application provide a flexible display panel and a manufacturing method thereof, which may improve the bending ability of the flexible display panel. Claim 1 of the invention provides a flexible display panel, including: a flexible substrate; a buffer layer formed on the flexible substrate; a metal layer at least formed on a second portion of the buffer layer; and a planarization layer, and a passivation layer formed between the planarization layer and the metal layer. The passivation layer and the planarization layer are made of organic materials. The flexible display panel includes a display area and a bending area in a lateral direction. The buffer layer includes a first portion and the second portion, the first portion corresponds to the display area, the second portion corresponds to the bending area, and a thickness of the second portion is less than a thickness of the first portion. The first portion includes a first SIOX layer, a SINX layer and a second SIOx layer successively disposed. The first SIOX layer is disposed on the flexible substrate, and the second portion includes a first SIOx layer. The second portion of the buffer layer does not include the SINx layer and the second SIOX layer. The thickness of the first SIOX layer of the second portion is less than a thickness of the first SIOx layer of the first portion. In an embodiment, the flexible display panel further includes a transition area in the lateral directio