LED Electrode Surface Roughness Matching for Recognition
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Solution Overview
Problem
Conventional LED structures face challenges in achieving consistent surface roughness of epitaxial layers under electrode pads, leading to poor image recognition and increased production downtime due to differences in light scattering and reflected intensities, making mass production difficult.
Innovation Solution
The LED structure incorporates a protrusive structure under the n-type electrode pad, which is equivalent to the light-emitting epitaxial structure under the p-type electrode pad, with the protrusive structure having a thickness less than or equal to the epitaxial structure, ensuring similar surface roughness and electrical properties, and a method involving etching with a photoresist mask to form these structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching process is used to form electrode pads, then electrode pads can be formed, but the surface roughness of epitaxial layers under different electrode pads becomes inconsistent, leading to poor image recognition
Solution Approach 1:
The patent applies local quality by treating different regions of the substrate differently during the etching process. Specifically, a first etching condition is used for the first electrode pad region while a second etching condition is used for the second electrode pad region, allowing each region to achieve the desired surface roughness characteristics independently. This resolves the contradiction by enabling localized control over surface properties rather than applying a uniform etching process across the entire substrate.
Solution Approach 2:
The patent employs parameter changes by modifying etching conditions (such as etch rate, temperature, or chemical composition) between different electrode pad regions. By changing the etching parameters for different areas, the patent achieves consistent surface roughness across all electrode pads, which directly improves image recognition rate during subsequent die bonding processes.
2Measurement precision
If etch parameters are adjusted to match surface roughness, then image recognition improves, but the process becomes complex and difficult to implement in mass production
Solution Approach 1:
The patent applies preliminary action by pre-defining different etching conditions for different electrode pad regions before the actual etching process begins. The method establishes a systematic approach where the first etching condition and second etching condition are predetermined based on the specific requirements of each electrode pad type, eliminating the need for complex real-time parameter adjustments during mass production.
Solution Approach 2:
The patent segments the etching process into distinct stages or regions, with each electrode pad type receiving its own optimized etching conditions. This segmentation allows for standardized processing of each region type, simplifying the overall manufacturing process while maintaining high image recognition rates, as each segment can be independently optimized and replicated.
3Manufacturing precision
If different etching conditions are applied to different electrode pads, then surface roughness consistency improves, but production time increases
Solution Approach 1:
The patent merges multiple etching operations into a single integrated process by applying different etching conditions to different regions simultaneously in one processing step. This approach achieves surface roughness consistency across all electrode pads without requiring separate etching steps for each electrode type, thereby maintaining high production efficiency while improving manufacturing precision.
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 approach enhances image recognition accuracy in die bonding and wire bonding, increases production efficiency, reduces inferior products, and improves surface texture issues by ensuring consistent surface roughness and electrical connectivity.
Implementation Method 1
a method involving etching with a photoresist mask to form these structures
Implementation Method 2
a method involving etching with a photoresist mask to form these structures
Implementation Method 3
the light scattering and reflected intensities of the p-type electrode pad 160 are inconsistent with those of the n-type electrode pad 170
Implementation Method 4
the light scattering and reflected intensities of the p-type electrode pad 160 are inconsistent with those of the n-type electrode pad 170
Data Source
AI summary
A light-emitting diode (LED) structure and a method for manufacturing the LED structure are disclosed for promoting the recognition rate of LED chips, wherein a roughness degree of the surface under a first electrode pad of a first conductivity type is made similar to that of the surface under a second electrode pad of a second conductivity type, so that the luster shown from the first electrode pad can be similar to that from the second electrode pad, thus resolving the poor recognition problem of wire-bonding machines caused by different lusters from the first and second electrode pads.