Light Emitting Device Connection Layers Voltage Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light emitting devices face challenges in minimizing the difference in operation voltages and optical properties among light emitting cells due to varying distances between cells and pads, which affects reliability and performance.
Innovation Solution
The design incorporates a light emitting device with a first and second light emitting part, each comprising multiple cells with specific semiconductor layers and electrode structures, along with connection layers and capping layers, to reduce voltage differences and enhance optical properties by optimizing the distances and connections between cells and pads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If light emitting cells are arranged at different distances from pads, then device layout flexibility is improved, but voltage difference among cells increases
Solution Approach 1:
The patent applies equipotentiality by designing connection layers with varying widths to compensate for distance differences. Cells at greater distances from pads are connected through wider connection layers, which have lower resistance, thereby equalizing the voltage supplied to all cells despite their different positions. This resolves the contradiction by maintaining voltage uniformity while allowing flexible cell arrangement.
Solution Approach 2:
The patent implements local quality by making connection layers have different widths at different locations. Specifically, connection layers connected to cells farther from pads are made wider than those connected to closer cells. This localized variation in connection layer geometry compensates for distance-induced voltage drops, allowing flexible layout while maintaining voltage uniformity across all cells.
2Reliability
If connection layers are made wider to reduce resistance, then voltage uniformity is improved, but device area increases
Solution Approach 1:
The patent applies local quality by making connection layers wider only in specific regions where needed. Connection layers connected to cells at greater distances from pads are made wider to reduce resistance, while connection layers for closer cells maintain standard width. This localized approach achieves voltage uniformity without unnecessarily increasing the overall device area.
Solution Approach 2:
The patent changes the geometric parameter (width) of connection layers based on their position and function. By adjusting the width parameter of connection layers, the patent optimizes the balance between resistance (affecting voltage uniformity) and area consumption, achieving voltage uniformity with minimal area increase.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
In one embodiment, a light emitting device comprises a first light emitting part including at least one light emitting cell; a second light emitting part including a plurality of light emitting cells, wherein each of the light emitting cells include a light emitting structure and a first electrode layer disposed under the light emitting structure; a plurality of pads disposed on the light emitting cell of the first light emitting part, wherein the pads are electrically connected to each of the light emitting cells of the first and second light emitting parts; a plurality of connection layers, each connection layer extending from a region under the light emitting cell of the first light emitting part to a region under the plurality of light emitting cells of the second light emitting part; a second electrode layer disposed under the light emitting cells of the first and second light emitting parts; an insulating layer disposed between the first and second electrode layers; and at least one gap part disposed between the at least one light emitting cell of the first light emitting part and the plurality of light emitting cells of the second light emitting part, wherein each of the plurality of connection layers extends through a region under the gap part and is electrically connected to each of the plurality of the light emitting cells of the second light emitting part.