# US 12,224,215 B2 · Display device and bonding detection method of display device

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- Number: US 12,224,215 B2
- Document ID: US12224215B2
- Status: Granted
- Kind: B2
- Application number: 17/403,428
- Filed: 2021-08-16
- Published: 2022-03-17
- Granted: 2025-02-11
- Earliest claimed: 2020-09-11
- Assignees: Chengdu Boe Optoelectronics Technology Co., Ltd.; Boe Technology Group Co., Ltd.
- Applicants: Chengdu BOE Optoelectronics Technology Co., Ltd.; BOE Technology Group Co., Ltd.
- Inventors: Chienpang Huang; Kaifang Zhu; Chuntong Jiang; Wei Li
- Web page: https://patentgrep.com/patent/US12224215B2

## CPC

- G09G 3/006: {Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays (testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309)}
- H10P 74/273: {Interconnections for measuring or testing, e.g. probe pads}
- G01R 31/2812: {Checking for open circuits or shorts, e.g. solder bridges; Testing conductivity, resistivity or impedance (of connections G01R31/66)}
- G09G 2300/043: Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver
- G09G 2380/02: Flexible displays
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

A display device and a bonding detection method of the display device are provided. The display device includes: a display panel, a flexible circuit board and a chip on flex with a control chip, where the display panel is connected with the flexible circuit board through the chip on flex in a bonding manner, a first detection line located on the display panel, a second detection line extending to the flexible circuit board from one end of the first detection line through the chip on flex, and a third detection line extending to the flexible circuit board from the other end of the first detection line through the chip on flex, where a path where the second detection line is located is provided with at least two first test pins, and a path where the third detection line is located is provided with at least two second test pins.

## Claims

### Claim 1

A display device, comprising:
a display panel;
a flexible circuit board;
a chip on film with a control chip, wherein the display panel is connected with the flexible circuit board through the chip on film in a bonding manner;
a first detection line located on the display panel;
a second detection line extending to the flexible circuit board from one end of the first detection line through the chip on film; and
a third detection line extending to the flexible circuit board from the other end of the first detection line through the chip on film;
wherein a path where the second detection line is located is provided with at least two first test pins, and a path where the third detection line is located is provided with at least two second test pins;
the second detection line and the third detection line are both closed loops;
wherein each of the closed loops comprises:
two first traces extending in a first direction on the chip on film,
a semi-closed first line frame located on the display panel, and
a semi-closed second line frame located on the flexible circuit board,
wherein the first direction is a direction pointing from the display panel to the flexible circuit board, and the first detection line is connected to the first line frame; and
two ends of the first line frame are correspondingly butted with two ends of the two first traces respectively, and two ends of the second line frame are correspondingly butted with the other two ends of the two first traces respectively.

### Claim 2 (depends on 1)

The display device according to claim 1, wherein the path where the second detection line is located is provided with the two first test pins, and the two first test pins are both located on the chip on film; and
the path where the third detection line is located is provided with the two second test pins, and the two second test pins are both located on the chip on film.

### Claim 3 (depends on 2)

The display device according to claim 2, wherein between the two first test pins of the each closed loop, line resistance across the display panel is different from line resistance across the flexible circuit board.

### Claim 4 (depends on 3)

The display device according to claim 3, wherein between the two first test pins of the each closed loop, a trace length across the display panel is different from a trace length across the flexible circuit board.

### Claim 5 (depends on 3)

The display device according to claim 3, wherein between the two first test pins of the each closed loop, a trace width across the display panel is different from a trace width across the flexible circuit board.

### Claim 6 (depends on 1)

The display device according to claim 1, wherein the second detection line and the third detection line are respectively located on two sides of the control chip; and the first detection line is in a semi-closed shape surrounding an edge of the display panel.

### Claim 7 (depends on 1)

The display device according to claim 1, wherein the display panel is circular or elliptical.

### Claim 8 (depends on 1)

A bonding detection method of the display device according to claim 1, comprising:
providing the display device; and
according to resistance between two first test pins on the path where the second detection line is located, resistance between two second test pins on the path where the third detection line is located, and resistance between any one of the first test pins on the path where the second detection line is located and any one of the second test pins on the path where the third detection line is located, determining a bonding state of the display panel and the chip on film, a bonding state of the chip on film and the flexible circuit board and a state of the display panel.

### Claim 9 (depends on 8)

The bonding detection method according to claim 8, wherein the second detection line and the third detection line are closed loops, the two first test pins are both located on the chip on film, and the two second test pins are both located on the chip on film; and
according to the resistance between the two first test pins on the path where the second detection line is located, the resistance between the two second test pins on the path where the third detection line is located, and the resistance between any one of the first test pins on the path where the second detection line is located and any one of the second test pins on the path where the third detection line is located, the determining the bonding state of the display panel and the chip on film, the bonding state of the chip on film and the flexible circuit board and the state of the display panel, comprises:
when the resistance between the two first test pins is a first resistance value and/or the resistance between the two second test pins is a second resistance value, determining that the display panel and the chip on film are in a poor bonding state, wherein the first resistance value is line resistance across the flexible circuit board between the two first test pins, and the second resistance value is line resistance across the flexible circuit board between the two second test pins;
when the resistance between the two first test pins is a third resistance value and/or the resistance between the two second test pins is a fourth resistance value, determining that the chip on film and the flexible circuit board are in a poor bonding state, wherein the third resistance value is line resistance across the display panel between the two first test pins, and the fourth resistance value is line resistance across the display panel between the two second test pins;
when the resistance between the two first test pins is a fifth resistance value and the resistance between the two second test pins is a sixth resistance value, determining that the display panel and the chip on film are in a bonding state, and the chip on film and the flexible circuit board are in a bonding state, wherein the fifth resistance value is a parallel connection value of the line resistance across the display panel and the line resistance across the flexible circuit board between the two first test pins, and the sixth resistance value is a parallel connection value of the line resistance across the display panel and the line resistance across the flexible circuit board between the two second test pins; and
when a resistance value between any one of the first test pins and any one of the second test pins is infinite, determining that the display panel is in a crack state; when the resistance value between any one of the first test pins and any one of the second test pins is not infinite, determining that the display panel is in a good state.

### Claim 10 (depends on 8)

The bonding detection method according to claim 8, wherein the second detection line and the third detection line are line segments, one of the first test pins on the path where the second detection line is located is located on the chip on film, the other first test pin is located on the flexible circuit board, one of the second test pins on the path where the third detection line is located is located on the chip on film, and the other second test pin is located on the flexible circuit board; and
according to the resistance between the two first test pins on the path where the second detection line is located, the resistance between the two second test pins on the path where the third detection line is located, and the resistance between any one of the first test pins on the path where the second detection line is located and any one of the second test pins on the path where the third detection line is located, the determining the bonding state of the display panel and the chip on film, the bonding state of the chip on film and the flexible circuit board and the state of the display panel, comprises:
when the resistance between the two first test pins on the path where the second detection line is located is infinite, and/or when the resistance between the two second test pins on the third detection line is infinite, determining that the chip on film and the flexible circuit board are in a poor bonding state; when the resistance between the two first test pins on the path where the second detection line is located is not infinite, and/or when the resistance between the two second test pins on the third detection line is not infinite, determining that the chip on film and the flexible circuit board are in a bonding state; and
when a resistance value between any one of the first test pins and any one of the second test pins is infinite, determining that the display panel and the chip on film are in a poor bonding state; when the resistance value between any one of the first test pins and any one of the second test pins is not infinite, determining that the display panel and the chip on film are in a bonding state.