LED Epitaxial Structure Bridging Electrode Transfer Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing process of flip-chip light emitting diodes (LEDs) faces challenges such as high technical requirements, high costs, low transferring efficiency, and low alignment precision, leading to potential cracking of insulating layers and current leakage due to the use of metal blocks that absorb light, which affects light emitting efficiency.
Innovation Solution
The LED device features a substrate with a unique epitaxial structure and bridging electrodes, including a flat operating zone for the ejector pin, which prevents damage to the insulating layer and maintains light efficiency by using a circular operating zone with a diameter of at least 60 μm, ensuring the bridging electrodes are not damaged during the transfer process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal blocks are disposed in the groove to prevent insulating layer damage, then the insulating layer is protected from cracking, but the metal blocks absorb light and reduce light emitting efficiency
Solution Approach 1:
The invention removes the harmful metal blocks from the groove and replaces them with an insulating structure. The insulating layer is extended into the groove region and patterned to form a protective structure that prevents cracking without absorbing light, thus extracting the harmful element (metal blocks) while maintaining the protective function.
Solution Approach 2:
The invention changes the material parameter from metal (light-absorbing) to insulating material (light-transparent). By modifying the material composition and optical properties of the protective structure, the solution maintains mechanical protection while eliminating light absorption, thereby resolving the contradiction between reliability and energy loss.
2Volume of moving object
If the operating zone is small to reduce device size, then the LED size is reduced, but the ejector pin operation becomes difficult and alignment precision decreases
Solution Approach 1:
The invention creates an asymmetric structure where the operating zone is selectively enlarged only in the central region where the ejector pin operates, while the rest of the LED maintains its small size. This asymmetric design allows the central operating zone to be at least 60 μm in diameter for easy manipulation, while the overall LED remains compact for high-density displays.
Solution Approach 2:
The invention addresses the size-precision contradiction by operating in different spatial dimensions. The operating zone is expanded in the lateral dimension (at least 60 μm diameter) specifically for the ejector pin interaction area, while the vertical integration and compact footprint are maintained through vertical stacking of functional layers, allowing precise manipulation without increasing overall device volume.
Data Source
AI summary
A light emitting diode device includes a substrate having a substrate surface, an epitaxial structure having an epitaxial surface opposite to the substrate surface, and a plurality of bridging electrodes disposed on the epitaxial surface. The epitaxial structure includes first, second and third light emitting units spacedly and sequentially disposed on the substrate surface. A projection of the second light emitting unit has a first edge and a second edge that is connected with and perpendicular to the first edge. The epitaxial surface has an operating zone on the second light emitting unit that is adapted to be pushed by an ejector pin. A length of the second edge is equal to or greater than a diameter of the operating zone.