# US 2021/0242056 A1 · Mass transfer method and mass transfer device thereof for micro led device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0242056 A1 - Document ID: US20210242056A1 - Status: Published application - Kind: A1 - Application number: 17/269,831 - Filed: 2020-06-15 - Published: 2021-08-05 - Earliest claimed: 2019-06-18 - Assignees: Beijing Boe Display Technology Co., Ltd.; Boe Technology Group Co., Ltd. - Applicants: Beijing BOE Display Technology Co., Ltd.; BOE Technology Group Co., Ltd. - Inventors: Bohua CHU; Bo ZHOU; Yanming LIU - Web page: https://patentgrep.com/patent/US20210242056A1 ## CPC - H10H 20/01: Manufacture or treatment - H10P 72/16: {Trays for chips} - H10H 20/018: {Bonding of wafers} - H10W 90/00: Package configurations - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract This disclosure discloses a mass transfer method and mass transfer device thereof for micro-LED devices, wherein the mass transfer method includes: coating a surface, provided with micro-LED devices, of an epitaxial substrate with a flexible covering solution; curing the flexible covering solution to form a flexible covering layer wrapping the micro-LED devices; turning over the epitaxial substrate with the flexible covering layer wrapping the micro-LED devices, for locating the epitaxial substrate on an upper side of the flexible covering layer; separating the epitaxial substrate from the micro-LED devices; butting a surface, provided with the micro-LED devices, of the flexible covering layer against a receiving substrate; turning over the receiving substrate in butt joint with the micro-LED devices, for locating the flexible covering layer on an upper side of the receiving substrate; and separating the flexible covering layer from the micro-LED devices. ## Claims ### Claim 1 A mass transfer method of micro-LED devices, comprising: coating a surface, provided with micro-Light-emitting diode (micro-LED) devices, of an epitaxial substrate with a flexible covering solution; curing the flexible covering solution to form a flexible covering layer wrapping the micro-LED devices; turning over the epitaxial substrate with the flexible covering layer wrapping the micro-LED devices, for locating the epitaxial substrate on an upper side of the flexible covering layer; separating the epitaxial substrate from the micro-LED devices, for enabling the flexible covering layer to serve as a carrier of the micro-LED devices; butting a surface, provided with the micro-LED devices, of the flexible covering layer against a receiving substrate; turning over the receiving substrate in butt joint with the micro-LED devices, for locating the flexible covering layer on an upper side of the receiving substrate; and separating the flexible covering layer from the micro-LED devices, for enabling the receiving substrate to serve as the carrier of the micro-LED devices. ### Claim 2 (depends on 1) The mass transfer method according to claim 1, wherein said coating the surface, provided with the micro-LED devices, of the epitaxial substrate with the flexible covering solution comprises: spraying the flexible covering solution on the surface, provided with the micro-LED devices, of the epitaxial substrate. ### Claim 3 (depends on 1) The mass transfer method according to claim 1, wherein the flexible covering solution comprises a base solution and a catalyst, and the base solution comprises polydimethylsiloxane, polyurethane acrylate or polymethyl methacrylate. ### Claim 4 (depends on 1) The mass transfer method according to claim 1, wherein a thickness of the flexible covering layer ranges from 0.5 mm to 1 mm. ### Claim 5 (depends on 1) The mass transfer method according to claim 1, wherein before said separating the flexible covering layer from the micro-LED devices, the method further comprises: heating the flexible covering layer for a set period of time at a set temperature. ### Claim 6 (depends on 5) The mass transfer method according to claim 5, wherein the set temperature at which the flexible covering layer is heated is higher than a temperature at which the flexible covering solution is cured, and the set period of time for which the flexible covering layer is heated is longer than a period of time for which the flexible covering solution is cured. ### Claim 7 (depends on 6) The mass transfer method according to claim 6, wherein the temperature at which the flexible covering solution is cured ranges from 60° C. to 100° C., and the period of time for which the flexible covering solution is cured ranges from 10 min to 35 min; and the set temperature at which the flexible covering layer is heated ranges from 120° C. to 140° C., and the set period of time for which the flexible covering layer is heated ranges from 30 min to 40 min. ### Claim 8 (depends on 1) The mass transfer method according to claim 1, wherein sacrificial layers are arranged between the micro-LED devices and the epitaxial substrate; and said separating the epitaxial substrate from the micro-LED devices comprises: irradiating the sacrificial layers by adopting a laser device to peel off the micro-LED devices from the epitaxial substrate. ### Claim 9 (depends on 1) The mass transfer method according to claim 1, wherein the flexible covering layer is provided with a first alignment mark, and the receiving substrate is provided with a second alignment mark and bonding layers; and said butting the surface, provided with the micro-LED devices, of the flexible covering layer against the receiving substrate comprises: fitting the surface, provided with the micro-LED devices, of the flexible covering layer to the receiving substrate in an aligned mode based on the first alignment mark and the second alignment mark; and bonding the receiving substrate and the micro-LED devices together through the bonding layers. ### Claim 10 (depends on 1) The mass transfer method according to claim 1, wherein a turning angle of turning over the epitaxial substrate with the flexible covering layer wrapping the micro-LED devices ranges from 175° to 185°; and a turning angle of turning over the receiving substrate in butt joint with the micro-LED devices ranges from 175° to 185°. ### Claim 11 Mass transfer equipment of micro-LED devices, comprising: coating equipment, configured to coat a surface, provided with micro-LED devices, of an epitaxial substrate with a flexible covering solution; curing equipment, configured to cure the flexible covering solution to form a flexible covering layer wrapping the micro-LED devices; turning equipment, configured to: turn over the epitaxial substrate with the flexible covering layer wrapping the micro-LED devices, for locating the epitaxial substrate on an upper side of the flexible covering layer; separate the epitaxial substrate from the micro-LED devices, for enabling the flexible covering layer to serve as a carrier of the micro-LED devices; butt a surface, provided with the micro-LED devices, of the flexible covering layer against a receiving substrate; and turn over the receiving substrate in butt joint with the micro-LED devices, for locating the flexible covering layer on an upper side of the receiving substrate; and separating equipment, configured to separate the flexible covering layer from the micro-LED devices, for enabling the receiving substrate to serve as the carrier of the micro-LED devices. ### Claim 12 (depends on 11) The mass transfer equipment according to claim 11, wherein the coating equipment is provided with a built-in spray head and the built-in spray head is configured to spray the flexible covering solution on the surface, provided with the micro-LED devices, of the epitaxial substrate. ### Claim 13 (depends on 11) The mass transfer equipment according to claim 11, wherein the turning equipment is provided with a built-in laser device and the built-in laser device is configured to separate the epitaxial substrate from the micro-LED devices for enabling the flexible covering layer to serve as the carrier of the micro-LED devices. ### Claim 14 (depends on 11) The mass transfer equipment according to claim 11, wherein the separating equipment is further configured to clean the receiving substrate carrying the micro-LED devices. ### Claim 15 (depends on 13) The mass transfer equipment according to claim 13, wherein the built-in laser device is further configured to bond the receiving substrate with the micro-LED devices through bonding layers of the receiving substrate. ### Claim 16 (depends on 8) The mass transfer method according to claim 8, wherein the sacrificial layers are arranged on a whole surface, facing the flexible covering layer, of the epitaxial substrate; or the sacrificial layers are arranged on a surface, facing the flexible covering layer, of the epitaxial substrate in one-to-one correspondence to each of the micro-LED devices. ### Claim 17 (depends on 9) The mass transfer method according to claim 9, wherein the bonding layers are arranged on a whole surface, facing the flexible covering layer, of the receiving substrate; or the bonding layers are arranged on a surface, facing the flexible covering layer, of the receiving substrate in one-to-one correspondence to each of the micro-LED devices. ### Claim 18 (depends on 1) A micro-LED display panel, fabricated by the mass transfer method according to claim 1.