# US 11,114,628 B2 · Method of manufacturing a flexible organic light-emitting diode (OLED) display panel by laser lift-off of a glass carrier through a planarization layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,114,628 B2 - Document ID: US11114628B2 - Status: Granted - Kind: B2 - Application number: 15/916,470 - Filed: 2018-03-09 - Published: 2019-06-06 - Granted: 2021-09-07 - Earliest claimed: 2017-12-05 - Assignees: Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. - Applicants: Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. - Inventors: Xiang Jin - Web page: https://patentgrep.com/patent/US11114628B2 ## CPC - H10K 71/00: Manufacture or treatment specially adapted for the organic devices covered by this subclass - G06F 3/0412: {Digitisers structurally integrated in a display} - H10K 59/1201: {Manufacture or treatment} - H10K 59/1213: {the pixel elements being TFTs} - H10K 71/221: {by lift-off techniques} - H10K 71/80: using temporary substrates - H10K 77/111: {Flexible substrates} - H10K 2102/311: {Flexible OLED} - Y02E 10/549: Organic PV cells - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A method of manufacturing flexible OLED display panel is provided. The method comprises following steps. Providing a glass carrier, sequentially forming a flexible substrate, a low temperature poly-Si layer and OLED element layer on a surface of the glass carrier; forming a planar layer on a second surface of the glass carrier which is away from the flexible substrate and obtaining a planning OLED display panel; removing the glass carrier by laser lift-off the planning OLED display panel and obtaining the flexible OLED display panel. The method could reduce the problem of lower peeling successful rate caused by the unevenly distributing in the flexible substrate during the laser lift-off process. ## Claims ### Claim 1 A method of manufacturing a flexible OLED display panel, comprising providing a glass carrier, sequentially forming a flexible substrate, a low temperature poly-Si layer and an OLED element layer on a surface of the glass carrier; forming a planarization layer on a second surface of the glass carrier which is away from the flexible substrate and obtaining a planarized OLED display panel; removing the glass carrier by laser lift-off the planarized OLED display panel, and obtaining the flexible OLED display panel; sequentially forming a packaging protecting layer, a flexible rear cover on the OLED element layer, the flexible substrate and the flexible rear cover forming an enclosed space for accommodating the OLED element layer and the packaging protecting layer; and forming a touch wire on the flexible substrate; or forming a first blocking layer on the flexible substrate, and forming the touch wire on the first blocking layer. ### Claim 2 (depends on 1) The method of manufacturing a flexible OLED display panel according to claim 1, wherein the planarization layer has laser transmittance ≥90% in 300-400 nm wavelength range. ### Claim 3 (depends on 2) The method of manufacturing a flexible OLED display panel according to claim 2, wherein the material of the planarization layer has laser absorption rate ≤6% in 300-400 nm wavelength range. ### Claim 4 (depends on 3) The method of manufacturing a flexible OLED display panel according to claim 3, wherein the roughness of the planarization layer is 0.05-0.3 μm. ### Claim 5 (depends on 4) The method of manufacturing a flexible OLED display panel according to claim 4, wherein the material of the planarization layer comprises at least one of organic material or inorganic material, the organic material comprises at least one of epoxy, acrylic resin and silicone; the inorganic material comprises at least one of silicon dioxide, magnesium fluoride, calcium fluoride and barium fluoride. ### Claim 6 (depends on 3) The method of manufacturing a flexible OLED display panel according to claim 3, wherein the material of the planarization layer comprises at least one of organic material or inorganic material, the organic material comprises at least one of epoxy, acrylic resin and silicone; the inorganic material comprises at least one of silicon dioxide, magnesium fluoride, calcium fluoride and barium fluoride. ### Claim 7 (depends on 1) The method of manufacturing a flexible OLED display panel according to claim 1, wherein the roughness of the planarization layer is Ra≤0.4 μm. ### Claim 8 (depends on 1) The method of manufacturing a flexible OLED display panel according to claim 1, wherein the thickness of the planarization layer is 50-120 μm. ### Claim 9 (depends on 8) The method of manufacturing a flexible OLED display panel according to claim 8, wherein the thickness of the glass carrier is 400-500 μm. ### Claim 10 (depends on 9) The method of manufacturing a flexible OLED display panel according to claim 9, wherein the planarization layer and the glass carrier which are stacking positioned have laser transmittance ≥40% in 300-400 nm wavelength range. ### Claim 11 (depends on 10) The method of manufacturing a flexible OLED display panel according to claim 10, wherein the material of the planarization layer comprises at least one of organic material or inorganic material, the organic material comprises at least one of epoxy, acrylic resin and silicone; the inorganic material comprises at least one of silicon dioxide, magnesium fluoride, calcium fluoride and barium fluoride. ### Claim 12 (depends on 11) The method of manufacturing a flexible OLED display panel according to claim 11, wherein the material of the planarization layer is silicon dioxide. ### Claim 13 (depends on 11) The method of manufacturing a flexible OLED display panel according to claim 11, wherein the step of forming the planarization layer which is mixing the material of the planarization layer and a solvent to obtain a sizing mixture; coating the sizing mixture on the second surface of the glass carrier which is away from the flexible substrate; and curing to form the planarization layer. ### Claim 14 (depends on 1) The method of manufacturing a flexible OLED display panel according to claim 1, wherein the material of the planarization layer comprises at least one of organic material or inorganic material, the organic material comprises at least one of epoxy, acrylic resin and silicone; the inorganic material comprises at least one of silicon dioxide, magnesium fluoride, calcium fluoride and barium fluoride. ### Claim 15 (depends on 14) The method of manufacturing a flexible OLED display panel according to claim 14, wherein the step of forming the planarization layer which is mixing the material of the planarization layer and a solvent to obtain a sizing mixture; coating the sizing mixture on the second surface of the glass carrier which is away from the flexible substrate; and curing to form the planarization layer. ### Claim 16 (depends on 1) The method of manufacturing a flexible OLED display panel according to claim 1, wherein during the laser lift-off, the laser wavelength is 300-400 nm; the laser energy is 290-350 mJ. ### Claim 17 (depends on 1) The method of manufacturing a flexible OLED display panel according to claim 1, wherein the packaging protecting layer encapsulating the OLED element and the low temperature poly-Si layer on the flexible substrate; the packaging protecting layer is formed by disposing an organic film and an inorganic film alternately. ### Claim 18 (depends on 1) The method of manufacturing a flexible OLED display panel according to claim 1, further comprising a second blocking layer positioned between the touch wire and the low temperature poly-Si layer.