GaN LED with Spark Gap and Reflective Electrode for ESD Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
GaN-based light emitting diodes face issues with electrostatic discharge, metal diffusion from solder pastes, and limited current spreading and light extraction efficiency, particularly in high-power applications, which affect reliability and manufacturing complexity.
Innovation Solution
A light emitting diode design incorporating a spark gap for electrostatic discharge protection, a current spreading layer with reflective properties, and an anti-diffusion reinforcing layer to prevent metal diffusion, along with a simplified fabrication process using laser scribing and electroless plating, allowing direct mounting on printed circuit boards without separate photomasks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a large area flip-chip type LED is used for high power output, then power output is improved, but current spreading becomes insufficient leading to non-uniform light generation
Solution Approach 1:
The patent divides the electrode structure into multiple segments: extension legs on the N-type semiconductor layer and a reflective electrode on the P-type semiconductor layer. This segmentation allows current to spread through multiple pathways across the large active area, ensuring uniform current distribution and light generation while maintaining high power output capability
Solution Approach 2:
The patent adds a reflective electrode layer on the P-type semiconductor layer, creating a two-dimensional current spreading network. This additional dimensional element works synergistically with the extension legs to achieve comprehensive current distribution across the large area active region, solving the uniformity problem in high-power LEDs
2Ease of operation
If electrode pads are directly exposed for mounting, then ease of mounting is improved, but metal diffusion from solder paste degrades reliability
Solution Approach 1:
The patent introduces an anti-diffusion layer as an intermediary between the electrode pads and the solder paste. This layer acts as a barrier that prevents metal diffusion from the solder paste into the semiconductor structure, while still allowing the electrode pads to be directly mounted. The anti-diffusion layer thus protects reliability without compromising mounting ease
3Manufacturing precision
If multiple photomasks are used for fabricating electrode structures, then manufacturing precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the formation of extension legs and reflective electrode patterns into a single photomask step. By designing the photomask to define both structures simultaneously, the patent reduces the number of separate photomasking operations needed, thereby simplifying the fabrication process while maintaining the precision required for proper current spreading and electrode alignment
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
The solution enhances electrostatic discharge protection, prevents metal diffusion, improves current spreading and light extraction efficiency, and simplifies the manufacturing process by reducing the need for photomasks and complex packaging, leading to more reliable and efficient high-power LED performance.
Implementation Method 1
a spark gap formed between a first leading end electrically connected to the first electrode pad region and a second leading end electrically connected to the second electrode pad region. The spark gap can achieve electrostatic discharge protection of the light emitting diode.
Implementation Method 2
The reflective electrode formed on the P-type semiconductor layer reflects light generated from the active layer to improve light extraction efficiency
Implementation Method 3
extension legs are formed on a region of the N-type semiconductor layer, which is exposed by etching the P-type semiconductor layer and the active layer, to facilitate current spreading
Implementation Method 4
A light emitting diode design incorporating a spark gap for electrostatic discharge protection, a current spreading layer with reflective properties, and an anti-diffusion reinforcing layer to prevent metal diffusion, along with a simplified fabrication process using laser scribing and electroless plating, allowing direct mounting on printed circuit boards
Data Source
AI summary
Disclosed are a light emitting diode (LED), an LED module including the same, and a method of fabricating the same. The light emitting diode includes a first conductive-type semiconductor layer; a second conductive-type semiconductor layer; an active layer interposed between the first conductive-type semiconductor layer and the second conductive-type semiconductor layer; a first electrode pad region electrically connected to the first conductive-type semiconductor layer; a second electrode pad region electrically connected to the second conductive-type semiconductor layer; and a spark gap formed between a first leading end electrically connected to the first electrode pad region and a second leading end electrically connected to the second electrode pad region. The spark gap can achieve electrostatic discharge protection of the light emitting diode.