Multi-Contact LED Grain Structure for Uniform Current Spreading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vertical light-emitting diodes face issues with non-uniform light emission leading to local hotspots and potential damage during wire bonding, and existing multi-conducting pillar technologies are fragile and costly, with limited applicability to phosphide and arsenide semiconductors due to high defect density and instability.
Innovation Solution
A light-emitting diode grain structure with multiple contact points featuring a P-type electrode, conductive base plate, ohmic contact metal points, mesh connection conductive layer, and N-type electrode pad, where the connection conductive layer does not form an ohmic contact with the N-type semiconductor layer, allowing current dispersion through ohmic contact metal points and reducing shading area with a mesh structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a single electrode pad is located at the center for wire bonding, then optical current dispersion is achieved and luminous efficiency is improved, but emitted light becomes excessively concentrated on the electrode pad causing local hot spots and potential damage
Solution Approach 1:
The single electrode pad is segmented into multiple electrode pads arranged in an array. This segmentation distributes the current entry points across multiple locations, preventing excessive concentration of light and heat on a single pad while maintaining effective current dispersion through the semiconductor layer.
2Reliability
If multiple reference lines are added to improve current dispersion, then current distribution is improved, but the shading area increases
Solution Approach 1:
The reference lines are designed with varying local properties: they have different widths, spacing, and patterns in different regions of the semiconductor layer. This allows optimization of current dispersion in specific areas while minimizing the total shading area, as the reference lines are denser where current dispersion is needed and sparser where light extraction is prioritized.
3Reliability
If multi-conducting pillar technology is used to disperse current uniformly, then current dispersion is improved and wire bonding safety is enhanced, but the structure becomes fine and fragile with complicated process and high cost
Solution Approach 1:
Instead of using complex three-dimensional conductive pillars with insulation coatings, the patent uses a planar array of electrode pads that replicate the current-dispersing function. This simplified two-dimensional structure achieves similar current distribution benefits without the manufacturing complexity, fragility, and high costs associated with vertical pillar structures.
4Reliability
If conductive pillars with thin insulation coatings are used, then current dispersion is improved, but the structure becomes fragile and susceptible to micro-cracks under external stress
Solution Approach 1:
The vulnerable thin insulation coating layer is completely removed from the design. The patent achieves current dispersion through multiple electrode pads and reference lines that operate without requiring insulating barriers, thereby eliminating the source of structural fragility and micro-crack formation that plagues pillar-based designs.
5Reliability
If multi-conducting pillar design is used for phosphide and arsenide semiconductors, then current dispersion may be achieved, but the chemical instability and high defect density make the process difficult and increase defect risk
Solution Approach 1:
The electrode pad array design is a universal solution that works effectively across different semiconductor material systems including nitride, phosphide, and arsenide. Unlike pillar structures that require precise insulation and are material-specific, the planar electrode pad configuration provides robust current dispersion that adapts to the chemical properties and defect characteristics of various semiconductor materials without requiring specialized processing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design achieves uniform current dispersion and light distribution, enhances reliability by avoiding hotspot formation, and is suitable for nitride, phosphide, and arsenide semiconductors by reducing the risk of damage during packaging and improving light extraction efficiency.
Implementation Method 1
a plurality of ohmic contact metal points arranged on the N-type semiconductor layer in a spreading manner, wherein the plurality of ohmic contact metal points contacts with the N-type semiconductor layer
Implementation Method 2
a connection conductive layer covering the N-type semiconductor layer and being electrically connected to the plurality of ohmic contact metal points, wherein no ohmic contact is formed between the connection conductive layer and the N-type semiconductor layer
Implementation Method 3
a vertical light-emitting diode can emit high-efficiency axial light
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention provides a light-emitting diode grain structure with multiple contact points, including a P-type electrode (10), a conductive base plate (20), a light-emitting semiconductor layer (30), a plurality of ohmic contact metal points (40, 40A, 40B, 40C), a mesh-structured connection conductive layer (50), a connection point conductive layer (60), and an N-type electrode pad (70) electrically connected to the connection point conductive layer (60). The plurality of ohmic contact metal points (40, 40A, 40B, 40C) is arranged on an N-type semiconductor layer (33) in a spreading manner, and is contacted with the N-type semiconductor layer (33). No ohmic contact is formed between the connection conductive layer (50) and the N-type semiconductor layer (33). Accordingly, the metal points (40, 40A, 40B, 40C) and the connection conductive layer (50) can disperse a current, reduce a shading area, and improve the luminous efficiency and component reliability; and uniform light emission from a surface facilitates the light distribution uniformity of an original light source and exciting light after phosphor is coated.