Flip Chip LED Packaging With Offset Substrate Platform
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Solution Overview
Problem
In flip chip light emitting diodes, the solder used for encapsulation and electrode coupling can cause the P and N electrodes to shift, leading to short circuits and reduced light output efficiency due to light absorption.
Innovation Solution
A packaging structure featuring a substrate with a protruding platform and a reflecting cup, where the LED chip is mounted, and an insulation portion that divides the substrate to create separate electrodes, preventing solder overflow and ensuring proper electrode alignment and light reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solder is used for encapsulation and electrode coupling, then the electrodes can be mounted on the substrate, but the solder absorbs light generated from the light active layer reducing light output efficiency
Solution Approach 1:
The harmful light-absorbing solder is extracted from the light path by offsetting the substrates and confining solder to specific mounting regions away from the light-emitting area. This separates the solder's functional role in electrode coupling from its harmful optical effect, maintaining mounting stability while preserving light output efficiency.
2Reliability
If the substrate is divided into first and second substrates offset from each other, then solder-induced short circuits are prevented, but the device structure becomes more complex
Solution Approach 1:
The offset substrate structure serves multiple functions simultaneously: it prevents short circuits by separating electrode mounting regions, enables independent solder confinement for each electrode, and maintains mechanical stability. This multi-functionality justifies the increased structural complexity by delivering multiple reliability benefits from a single design feature.
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 prevents solder-induced short circuits and enhances light output efficiency by maintaining electrode alignment and reflecting light effectively.
Implementation Method 1
a reflecting cup 20 located on the substrate 10... enhancing light output efficiency by maintaining electrode alignment and reflecting light effectively
Data Source
AI summary
A flip chip light emitting diode (LED) packaging structure, including a substrate, an LED chip including a P electrode and a N electrode. A protruding platform is formed in a center of the substrate. The protruding platform includes a first connecting portion and a second connecting portion electrically insulating from each other. The P electrode and the N electrode is conductively fixed to the protruding platform by solder, and a bottom edge of the P electrode and the N electrode are beyond a top edge of the protruding platform.