Backplane Substrate Valley Structure for Precise LED Mounting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing technologies for display devices, particularly those using inorganic light emitting diode elements, face challenges in properly adjusting image color and luminance due to the variation in light color with driving current, and the residual protective layers on backplane substrates can cause mounting defects during the assembly of light emitting elements.
Innovation Solution
A backplane substrate design with a support substrate, circuit layer, electrode layer, and bank layer, including a valley structure that limits the protective layer's placement, preventing residual protective layers from interfering with the anode and cathode pads and ensuring accurate mounting of light emitting elements, while also addressing color variation issues by precise current control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective layer is applied to cover both surfaces of the backplane substrate during transfer, then the substrate is protected from foreign matter or damage, but the protective layer may remain as residue causing mounting defects of the light emitting elements
Solution Approach 1:
The protective layer is divided into a first protective layer covering the front surface and a second protective layer covering the rear surface, allowing selective removal of the first protective layer while retaining the second, thus preventing residue on the anode and cathode while maintaining protection during transfer
Solution Approach 2:
The first protective layer is removed before mounting the light emitting elements, in advance of the mounting process, to prevent any residue from interfering with the mounting precision and to eliminate the need for post-removal cleaning steps
2Illumination intensity
If the magnitude of driving current is adjusted to control luminance, then the brightness can be controlled, but the color of light emitted from the inorganic light emitting diode element varies causing improper image display
Solution Approach 1:
Different subpixels are assigned different primary colors (red, green, blue) with fixed emission spectra, allowing the system to maintain color accuracy by combining these fixed-color subpixels in various intensities rather than varying the color of individual wide-spectrum LEDs
Solution Approach 2:
The system changes the parameter being controlled from the color temperature of individual LEDs to the intensity combination of multiple fixed-color subpixels, achieving luminance control while maintaining color accuracy through additive color mixing
Data Source
AI summary
A backplane substrate, a display device, and a tiled display device are provided. The backplane substrate of a display device includes subpixels. The backplane substrate includes a support substrate, a circuit layer on a first surface of the support substrate and including pixel drivers corresponding to the subpixels, respectively, an electrode layer on the circuit layer and including an anode and a cathode corresponding to an emission area of each of the subpixels, a bank layer on the circuit layer and corresponding to an area around the emission area of each of the subpixels, and a valley spaced from edges of the support substrate and penetrating at least the bank layer.