Segmented Pixel Anodes for Higher-Yield LED Arrays

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Solution Overview

Problem

Existing LED manufacturing processes face challenges with low yield and high costs due to defects in monolithic arrays and complex pick-and-place methods for singulated LEDs, leading to non-operational pixels and reliability concerns.

Innovation Solution

The implementation of segmented anodes in LED devices, which allow for localized current distribution and electrical isolation of defective pixels, improving yield and reducing manufacturing complexity by isolating defects post-integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If monolithic arrays of LEDs are used, then device integration is improved, but yield decreases due to defects affecting entire large-die pixels

Engineering Contradiction:

Improvedevice integrationVSAvoidyield

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The anode of each pixel is divided into multiple segmented anodes (e.g., first segmented anode, second segmented anode) that contact different regions of the p-type layer. This segmentation allows defective regions to be electrically isolated while maintaining functionality of non-defective regions, thereby improving yield without sacrificing integration.

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If singulated LED pixels are transferred and attached to backplane, then manufacturing flexibility is improved, but process complexity and cost increase due to sophisticated pick-and-place requirements

Engineering Contradiction:

Improvemanufacturing flexibilityVSAvoidprocess complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

Multiple LED pixels are integrated together on a single backplane to form an integrated LED device. This merging approach eliminates the need for individual pick-and-place operations for each pixel, reducing process complexity and cost while maintaining manufacturing flexibility.

Inventive Principle:

Principle #5Merging (Combining)

3Measurement precision

If individual LED testing and sorting is performed, then defect detection is improved, but productivity decreases due to additional processing steps

Engineering Contradiction:

Improvedefect detectionVSAvoidproductivity

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

Testing and sorting are performed on the integrated LED device containing multiple pixels before final assembly, rather than on individual pixels. This preliminary action allows defect detection at the integrated level, maintaining productivity while enabling defect identification through the segmented anode structure that allows selective activation of non-defective regions.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12419137B2Light emitting diodes with segmented anodes by pixel

Publication Date: 2025.09.16 LUMILEDS SINGAPORE PTE LTD

AI summary

A light emitting diode (LED) device comprises a plurality of pixels on a backplane, each pixel comprising: semiconductor layers, which include an N-type layer, an active region, and a P-type layer; a cathode electrically contacting the N-type layer; an anode comprising anode segments electrically contacting respective portions of the P-type layer; one or more dielectric materials insulating: the active region and the P-type layer from the cathode, the anode segments from each other, and the anode segments from the cathode; and a plurality of interconnects, each respective interconnect affixing a respective anode segment to the backplane. Methods of making and use the devices are also provided.