# US 11,910,692 B2 · Display device including test element group, and method for inspecting defect of display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,910,692 B2 - Document ID: US11910692B2 - Status: Granted - Kind: B2 - Application number: 17/462,705 - Filed: 2021-08-31 - Published: 2022-06-02 - Granted: 2024-02-20 - Earliest claimed: 2020-11-27 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Seunghyun Park; Yun-Mo Chung - Web page: https://patentgrep.com/patent/US11910692B2 ## CPC - G01R 31/2884: {using dedicated test connectors, test elements or test circuits on the IC under test (G01R31/2855 takes precedence)} - H10K 59/1315: {comprising structures specially adapted for lowering the resistance} - H10K 59/80516: {combined with auxiliary electrodes, e.g. ITO layer combined with metal lines} - H10K 59/80517: {Multilayers, e.g. transparent multilayers} - H10K 59/80521: {characterised by their shape} - H10K 59/80522: {combined with auxiliary electrodes} - H10K 59/88: Dummy elements, i.e. elements having non-functional features - H10K 71/70: Testing, e.g. accelerated lifetime tests - H10K 59/1201: {Manufacture or treatment} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract A display device includes a substrate including a display area and a test area adjacent to the display area, a lower electrode disposed in the display area on the substrate, a common layer disposed on the lower electrode, an upper electrode disposed on the common layer; and a test element group. The test element group includes a plurality of electrode patterns disposed in a same layer as the lower electrode and in the test area on the substrate, a test common layer disposed in a same layer as the common layer and on the electrode patterns, where a plurality of openings is defined through the test common layer to expose a part of each of the electrode patterns, and an electrode layer disposed in a same layer as the upper electrode, on the test common layer, and in contact with the electrode patterns through the openings. ## Claims ### Claim 1 A display device comprising: a substrate including a display area and a test area adjacent to the display area; a lower electrode disposed in the display area on the substrate; a light emitting layer disposed on the lower electrode; a common layer disposed on the light emitting layer; an upper electrode disposed on the common layer; and a test element group including: a plurality of electrode patterns disposed in a same layer as the lower electrode and in the test area on the substrate; a test common layer disposed in a same layer as the common layer and on the plurality of electrode patterns, wherein a plurality of openings is defined through the test common layer to expose a part of each of the plurality of electrode patterns; and an electrode layer disposed in a same layer as the upper electrode, on the test common layer, and in contact with the plurality of electrode patterns through the plurality of openings. ### Claim 2 (depends on 1) The display device of claim 1, wherein the test element group further includes: a plurality of conductive patterns disposed in the test area on the substrate. ### Claim 3 (depends on 2) The display device of claim 2, further comprising: a via layer disposed between the substrate and the plurality of electrode patterns, wherein the plurality of electrode patterns are electrically connected to the plurality of conductive patterns through contact holes defined in the via layer, respectively. ### Claim 4 (depends on 2) The display device of claim 2, wherein the plurality of conductive patterns are spaced apart from each other, and the plurality of electrode patterns are spaced apart from each other. ### Claim 5 (depends on 1) The display device of claim 1, wherein the test area surrounds at least a part of the display area. ### Claim 6 (depends on 1) The display device of claim 1, wherein the common layer extends from the display area to the test area, an extending part of the common layer in the test area defines the test common layer, the upper electrode extends from the display area to the test area, and an extending part of the upper electrode in the test area defines the electrode layer. ### Claim 7 (depends on 1) The display device of claim 1, wherein the lower electrode and the plurality of electrode patterns include a same material as each other. ### Claim 8 (depends on 1) The display device of claim 1, wherein each of the lower electrode and the plurality of electrode patterns has a stacked structure including ITO/Ag/ITO. ### Claim 9 (depends on 1) The display device of claim 1, wherein the upper electrode and the electrode layer include a same material as each other. ### Claim 10 (depends on 1) The display device of claim 1, wherein the test element group further includes: a plurality of conductive patterns disposed in the test area on the substrate, and wherein the display device further comprises: source electrode and a drain electrode disposed in a same layer as the plurality of conductive patterns in the display area on the substrate. ### Claim 11 (depends on 10) The display device of claim 10, wherein the plurality of conductive patterns, the source electrode, and the drain electrode include a same material as each other. ### Claim 12 (depends on 1) The display device of claim 1, wherein a part of an electrode pattern, which is located at a first end of the test element group, among the plurality of electrode patterns defines a first test pad of the test element group, and a part of an electrode pattern, which is located at a second end of the test element group among the plurality of electrode patterns, defines a second test pad of the test element group. ### Claim 13 (depends on 1) The display device of claim 1, wherein when viewed in a plan view, the test element group has a tetragon shape where one side is opened.