LED Epitaxy with Exposed Semiconductor Layers for Direct Bonding
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Solution Overview
Problem
Conventional LED packaging technologies face issues with heat transfer due to differing heat transfer coefficients between the LED die and packaging body, leading to potential damage in high-temperature environments, and require wire bonding which can result in insufficient adhesion, wire breakage, and reduced light emission.
Innovation Solution
A light emitting element and module design that eliminates the need for wire bonding by using epitaxy layers with exposed semiconductor layers and large-area bonding pads or conducting trenches for direct bonding to a circuit board or heat sink, enhancing heat conduction and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wire bonding is used to connect LED to substrate, then electrical connection is achieved, but adhesion is insufficient and wires may break
Solution Approach 1:
The patent removes the wire bonding process entirely from the LED packaging structure. Instead of using separate wires to connect the LED chip to the substrate, the LED chip is directly bonded to the substrate through its electrode regions, eliminating the intermediate wire connection that causes adhesion problems and structural complexity.
Solution Approach 2:
The patent merges the electrical connection function with the mechanical bonding structure. The electrode regions of the LED chip are directly integrated with the substrate contact regions, combining what were previously separate functions (wire connection and chip mounting) into a single direct bonding interface.
2Illumination intensity
If wire bonding is used, then electrical connection is established, but light emission is reduced due to shield effect
Solution Approach 1:
The patent extracts and removes the wire structures from the LED packaging design. By eliminating the gold or aluminum wires that previously connected the chip to the substrate, the light path is cleared of obstructing elements, allowing maximum light emission without the shield effect caused by wire structures.
3Temperature
If conventional packaging body is used, then LED chip is protected, but heat transfer is insufficient due to different heat transfer coefficients
Solution Approach 1:
The patent applies local quality enhancement by creating direct thermal contact pathways between the LED chip and the substrate. The contact regions are specifically designed with high thermal conductivity materials and direct physical contact, providing localized high-performance heat transfer zones that match the thermal requirements of the LED chip without requiring a complete redesign of the entire packaging body.
Solution Approach 2:
The patent employs asymmetric design in the thermal management structure, where the substrate and contact regions are specifically engineered with thermal conductivity properties that complement the LED chip's heat generation characteristics. The heat transfer path is optimized to be more efficient in the critical chip-to-substrate interface region, creating an asymmetric thermal management approach that addresses the heat transfer coefficient mismatch.
4Illumination intensity
If flip-chip bonding is used, then light emission efficiency is enhanced and heat conduction is improved, but die-bonding machine of high precision is required increasing cost
Solution Approach 1:
The patent segments the bonding interface into distinct electrode regions and contact regions, allowing for standardized, modular design. This segmentation enables the use of conventional bonding equipment by breaking down the bonding process into manageable, precision-controlled stages that don't require ultra-high precision die-bonding machines, thus reducing manufacturing costs while maintaining light emission efficiency.
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 improves heat conduction efficiency, reduces the risk of wire-related issues, and allows for miniaturization without size limitations, while enhancing light emitting efficiency and brightness, and enabling the formation of various colors without the need for a plastic shell.
Implementation Method 1
enhancing heat conduction
Data Source
AI summary
A light emitting element including an epitaxy layer, at least one first electrode, at least one second electrode, a first bonding pad and a second bonding pad. The epitaxy layer includes in sequence a first semiconductor layer, an active layer and a second semiconductor layer, and the first semiconductor layer has an exposed portion exposed from the second semiconductor layer and the active layer. The first electrode is disposed at the exposed portion. The second electrode is disposed at the second semiconductor layer. The first bonding pad is connected with the first electrode. The second bonding pad is connected with the second electrode. Two light emitting elements with different structures and the light emitting module utilizing the light emitting elements mentioned above are also disclosed.