# US 12,008,930 B2 · Display panel and manufacturing method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,008,930 B2 - Document ID: US12008930B2 - Status: Granted - Kind: B2 - Application number: 17/434,723 - Filed: 2021-06-08 - Published: 2024-01-18 - Granted: 2024-06-11 - Earliest claimed: 2021-05-08 - Assignees: Wuhan China Star Optoelectronics Technology Co., Ltd.; Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. - Applicants: Wuhan China Star Optoelectronics Technology Co., Ltd.; Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. - Inventors: Yang Zhang - Web page: https://patentgrep.com/patent/US12008930B2 ## CPC - G09F 9/301: {flexible foldable or roll-able electronic displays, e.g. thin LCD, OLED} - G09F 9/30: in which the desired character or characters are formed by combining individual elements (panels comprising a number of electrodes in a single cell controlling light arriving from an independent light source, e.g. electro-optical or magneto-optical cell, G02F1/00) - G09F: DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS ## Abstract The present invention provides a display panel and a manufacturing method of the display panel. The display panel includes a first film layer, a second film layer, and a bonding layer which are arranged in a first folding region. When the display panel is in a bent state, first tangential forces of the first film layer exerted on a first surface of the bonding layer and second tangential forces of the second film layer exerted on the second surface of the bonding layer point to a center of the first folding region. The bonding layer is bent in advance, and the bonding layer is bonded with the first film layer in the bent state and bonded with the second film layer in a flat state, so bending stresses of the bonding layer are relieved. ## Claims ### Claim 1 A display panel, comprising: a first folding region; and two non-folding regions located at two sides of the first folding region; wherein the first folding region is provided with a first film layer, a second film layer, and a bonding layer between the first film layer and the second film layer; wherein the bonding layer comprises a first surface in contact with the first film layer and a second surface in contact with the second film layer; and when the display panel is in a bent state, first tangential forces of the first film layer exerted on the first surface and second tangential forces of the second film layer exerted on the second surface point to a center of the first folding region. ### Claim 2 (depends on 1) The display panel according to claim 1, wherein when the display panel is in the bent state, the first surface is arranged close to a concave direction of the first folding region, and the second surface is arranged close to a convex direction of the first folding region; and when the display panel is in a flat state, the first tangential forces on the first surface point to the center of the first folding region, and the second tangential forces on the second surface are zero. ### Claim 3 (depends on 2) The display panel according to claim 2, wherein when the display panel is in the bent state, an orthographic projection of the second surface projected on the first surface is located within the first surface; and when the display panel is in the flat state, an orthographic projection of the first surface projected on the second surface is located within the second surface. ### Claim 4 (depends on 2) The display panel according to claim 2, wherein when the display panel is in the bent state or in the flat state, an orthographic projection of the first surface projected on the second surface is located within the second surface. ### Claim 5 (depends on 1) The display panel according to claim 1, wherein when the display panel is in a rest state, a bending curvature of the display panel is greater than zero. ### Claim 6 (depends on 1) The display panel according to claim 1, further comprising a second folding region arranged corresponding to the first folding region, and a plurality of film layers in the second folding region and the film layers in the first folding region are bent toward a same direction. ### Claim 7 (depends on 1) The display panel according to claim 1, wherein the bonding layer comprises an adhesive film body, and a material of the adhesive film body is an optical adhesive. ### Claim 8 A manufacturing method of a display panel, the display panel comprising a first folding region and two non-folding regions located at two sides of the first folding region, the manufacturing method of the display panel comprising following steps: providing a bonding layer, wherein the bonding layer comprises a bending section arranged corresponding to the first folding region and a first section and a second section arranged corresponding to the non-folding regions, and a bending curvature of the bending section is a first curvature; providing a first film layer, and attaching the first film layer to a first surface of the bonding layer to form a composite film layer; and setting the composite film layer in a flat state, and forming a second film layer on a second surface of the bonding layer away from the first film layer, wherein a curvature formed by the composite film layer and the second film layer is a second curvature, and the first curvature is greater than the second curvature; wherein when the display panel is in a bent state, first tangential forces of the first film layer exerted on the first surface and second tangential forces of the second film layer exerted on the second surface point to a center of the first folding region. ### Claim 9 (depends on 8) The manufacturing method of the display panel according to claim 8, wherein the step of providing the bonding layer, in which the bonding layer comprises the bending section arranged corresponding to the first folding region and the first section and the second sections arranged corresponding to the non-folding regions, and the bending curvature of the bending section is the first curvature, comprises following steps: providing a bonding material layer, wherein the bonding material layer comprises a bending section arranged corresponding to the first folding region and a first section and a second section arranged corresponding to the non-folding regions; placing the bonding material layer on a first jig for bending the bonding material layer to make the bending curvature of the bending section be the first curvature; and separating the bonding material layer from the first jig to obtain the bonding layer. ### Claim 10 (depends on 9) The manufacturing method of the display panel according to claim 9, wherein the bonding material layer comprises a first protective film, a second protective film, and an adhesive film body located between the first protective film and the second protective film; and the step of placing the bonding material layer on a first jig for bending the bonding material layer to make the bending curvature of the bending section be the first curvature comprises following steps: placing the adhesive material layer on the first jig which is located on one side close to the first protective film; removing the second protective film; and bending the first protective film and the adhesive film body on the first jig to make the bending curvature of the bending section be the first curvature. ### Claim 11 (depends on 10) The manufacturing method of the display panel according to claim 10, wherein after the step of removing the second protective film, the manufacturing method further comprises: forming a third protective film on one side of the adhesive film body away from the first protective film. ### Claim 12 (depends on 11) The manufacturing method of the display panel according to claim 11, wherein the step of setting the composite film layer in the flat state and forming the second film layer on the second surface of the bonding layer away from the first film layer comprises: removing the third protective film; setting the composite film layer in the flat state; and forming the second film layer on the second surface of the bonding layer away from the first film layer. ### Claim 13 (depends on 9) The manufacturing method of the display panel according to claim 9, wherein the step of placing the bonding material layer on the first jig for bending the bonding material layer comprises following steps: placing the bonding material layer on the first jig; and heating the bonding material layer while bending the bonding material layer. ### Claim 14 (depends on 13) The manufacturing method of the display panel according to claim 13, wherein a heating temperature ranges from 50° C. to 80° C. ### Claim 15 (depends on 14) The manufacturing method of the display panel according to claim 14, wherein the step of heating the bonding material layer comprises following steps: heating the bonding material layer from a first temperature to a second temperature at a first temperature rising rate; and heating the bonding material layer from the second temperature to a third temperature at a second temperature rising rate. ### Claim 16 (depends on 15) The manufacturing method of the display panel according to claim 15, wherein the first temperature rising rate is greater than the second temperature rising rate. ### Claim 17 (depends on 13) The manufacturing method of the display panel according to claim 13, wherein the first jig comprises a first convex portion, the first convex portion is arranged corresponding to the first folding region, and the first folding region is arranged corresponding to the bending section. ### Claim 18 (depends on 13) The manufacturing method of the display panel according to claim 13, wherein the display panel further comprises a second folding region arranged corresponding to the first folding region, and a plurality of film layers in the second folding region and the film layers in the first folding region are bent toward a same direction. ### Claim 19 (depends on 18) The manufacturing method of the display panel according to claim 18, wherein the first jig comprises a first convex portion and a second convex portion; the first convex portion is arranged corresponding to the first folding region; and the second convex portion is arranged corresponding to the second folding region. ### Claim 20 (depends on 9) The manufacturing method of the display panel according to claim 9, wherein the step of placing the bonding material layer on the first jig for bending the bonding material layer further comprises following steps: applying an inert gas on the bonding material layer; and placing the bonding material layer on the first jig for a first time period.