Light Emitting Device Anti-Crack Layer and Metal Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current light emitting diodes (LEDs) face challenges in increasing luminance, reducing operating voltage, and preventing cracks during the cutting process, while maintaining superior adhesion and electrical properties.
Innovation Solution
The design incorporates a conductive substrate, a window layer to reduce reflectivity differences, a roughness pattern on the second semiconductor layer for improved light extraction, and an anti-crack layer to prevent cracking during chip cutting, along with metal contact portions that pass through a transparent electrode layer to reduce forward voltage and enhance adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the wafer is cut on a light emitting device basis, then the device can be mounted as a surface mount device, but cracks may be generated during the cutting process
Solution Approach 1:
The patent divides the wafer into multiple light emitting devices through a cutting process, creating individual chips that can be mounted as surface mount devices. This segmentation enables standardized manufacturing while the anti-crack layer prevents damage during separation
Solution Approach 2:
The patent applies an anti-crack layer to the light emitting device before the wafer cutting process. This layer acts as a protective cushion that prevents cracks from forming during the subsequent cutting operation, ensuring device reliability while enabling easy manufacturing
2Use of energy by stationary object
If the forward voltage is reduced, then the operating voltage decreases, but the luminous efficacy may be affected
Solution Approach 1:
The patent modifies the electrical parameters of the light emitting device by reducing the forward voltage through specific electrode and contact layer configurations. This parameter change lowers the operating voltage while the patent ensures luminous efficacy is maintained through optimized material composition and layer structure
3Illumination intensity
If the luminance is increased, then the light output improves, but the forward voltage may increase
Solution Approach 1:
The patent optimizes multiple parameters simultaneously including the active layer composition, electrode structure, and contact layer properties to increase luminance while controlling forward voltage. Through coordinated parameter optimization rather than single-parameter changes, the patent achieves higher light output without proportional voltage increase
4Reliability
If the electrodes have superior adhesion, then the electrical properties improve, but the manufacturing complexity increases
Solution Approach 1:
The patent employs composite material structures for the electrodes and contact layers, combining multiple materials with complementary properties to achieve superior adhesion and electrical characteristics. These composite structures, while somewhat complex, follow standardized patterns that facilitate manufacturing
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 configuration enhances luminous efficacy, reduces forward voltage by about 10%, prevents cracking during chip cutting, and maintains superior electrical and adhesion properties, thereby improving the overall performance of the light emitting device.
Implementation Method 1
a roughness pattern on the second semiconductor layer for improved light extraction
Implementation Method 2
a window layer to reduce reflectivity differences
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a light emitting device including a conductive substrate, a first electrode layer disposed on the conductive substrate, a light emitting structure disposed on the first electrode layer, the light emitting structure including a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer, a second electrode layer electrically connected to the second semiconductor layer, and an anti-crack layer disposed on a boundary on which the light emitting structure is segmented on a chip basis, wherein the anti-crack layer is disposed under the light emitting structure and includes a metal material contacting the light emitting structure.