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A method for efficiently detecting dead pixels of small-pitch COB display modules

A display module, small spacing technology, applied in the field of display screen, can solve the problems of high time cost, increased production cost, damage, etc., and achieve the effect of saving time and production cost, reducing the workload of inspection, and having broad application prospects.

Active Publication Date: 2021-07-16
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This constitutes its high-resolution advantage, but at the same time it also causes another disadvantage: easy to produce pixel dead pixels
There are two common solutions. One is to test all the chips one by one before the LED chips are fixed on the display module substrate and not packaged, so as to eliminate the bad pixels. This solution avoids quality problems after packaging. The packaging is destructive, but the time cost is high, the workload is heavy, and the production cost is increased; the second is that after the packaging is completed and the control circuit is installed, the circuit control is used to perform the overall lighting test of the display screen and individually test the pixels. The control circuit can quickly find the dead pixel, but repairing the bad pixel will partially destroy the completed packaging, and the second packaging will destroy the original consistency

Method used

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  • A method for efficiently detecting dead pixels of small-pitch COB display modules
  • A method for efficiently detecting dead pixels of small-pitch COB display modules
  • A method for efficiently detecting dead pixels of small-pitch COB display modules

Examples

Experimental program
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Effect test

Embodiment 1

[0050] Taking the P5.0 small-pitch 5cm×5cm COB display module unit as an example, the shape of the small-pitch COB display module substrate 15 is square. For the detection circuit, RGB three chips are preferred to reserve independent row-series-column-parallel circuits. All the figures only draw part of the chips as a schematic representation, and only a single color chip is drawn as a schematic representation in the row detection and dichotomy stages.

[0051] This method comprises the following steps:

[0052] (1) if figure 1 As shown, the small-pitch COB display module substrate 15 reserves a row-series-column-parallel circuit in advance. Row-series means that the electrodes of the color light chip pads 14 in each row are connected in series, that is, the positive pole of each pad is in phase with the negative pole of the previous pad. Connection, the negative pole is connected to the positive pole of the next pad, and the pads on both sides lead out two pins to form a row...

Embodiment 2

[0063] Taking the P5.0 small-pitch 5cm×5cm COB display module unit as an example, the shape of the small-pitch COB display module substrate 15 is square. For the detection circuit, RGB three chips are preferred to reserve independent row-series-column-parallel circuits. All the figures only draw part of the chips as a schematic representation, and only a single color chip is drawn as a schematic representation in the row detection and dichotomy stages.

[0064] The detection steps are generally the same as in Example 1, except that in this embodiment, the whole row of green chip (G) 19 is turned on and tested and found that there are two rows that are not lit, indicating that there are pixels of green chip (G) 19 in both rows Dead pixel chip 23, which belongs to the situation where there are pixel dead pixels in two rows or even multiple rows (n rows), and then the two rows are detected separately, and the two green chips can be found by performing up to 4n dichotomous detectio...

Embodiment 3

[0066] Taking the P5.0 small-pitch 5cm×5cm COB display module unit as an example, the shape of the small-pitch COB display module substrate 15 is square. For the detection circuit, RGB three chips are preferred to reserve independent row-series-column-parallel circuits. All the figures only draw part of the chips as a schematic representation, and only a single color chip is drawn as a schematic representation in the row detection and dichotomy stages.

[0067] The detection steps are generally the same as in Example 1, except that when this embodiment uses the dichotomy method to test the green light chip (G) 19, the two ends are not bright when tested separately, indicating that there are green light chips (G) 19 at both ends. For the dead pixel chips 23, both sides need to perform further dichotomy processing and detection on the undetected chips until all the dead pixel chips 23 of the green light chips (G) 19 are found. This is the case of multiple bad points in a single ...

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Abstract

The invention discloses a method for efficiently detecting dead pixels of a small-pitch COB display module, comprising the steps of: reserving independent detection circuits for three RGB chips on the COB display module substrate; performing crystal bonding on the RGB chips; Check the overall circuit of the R circuit, G circuit or B circuit to determine the line where the bad point is located; dichotomy positioning efficiently locates the bad point; replaces and repairs the bad point; retests until the circuit is all lit up; repeats the steps for the remaining two color chips to locate Repair bad points; Silicone encapsulation of COB display module; cutting and cutting off the reserved circuit of COB display module; the method of the present invention uses the reserved circuit to conduct simple and quick overall detection before module packaging, and then uses the dichotomy method to quickly locate and Repairing dead pixels and disconnecting reserved circuits after encapsulation will not affect the actual application of the display module, and eliminate quality risks for the next step of control circuit installation, which has important practical significance in the field of small-pitch display.

Description

technical field [0001] The invention relates to the technical field of display screens, in particular to a method for efficiently detecting dead pixels of small-pitch COB display modules. Background technique [0002] Small-pitch display technology, that is, light-emitting diode (LED) miniaturization and matrix technology, refers to the integration of high-density micro-sized LED arrays on a single display module, that is, the LED structure design is thinned, miniaturized and arrayed. It makes each pixel of the LED display addressable and individually driven to light up. It can be regarded as a miniature version of the current LED, reducing the pixel distance from centimeters to millimeters. The main advantages of small-pitch COB display modules are: good reliability, inheriting the characteristics of long life, high reliability, and high efficiency of conventional LEDs; high-definition resolution, based on the advantages of small pitches reaching millimeter or even micron l...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G09G3/00
CPCG09G3/006
Inventor 李宗涛汤勇颜才满饶龙石卢汉光余彬海
Owner SOUTH CHINA UNIV OF TECH
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