Jaekyun Kim | Advanced View Technology Inc: Is wafer bonding holding back the commercialization of ultra-bright AR/VR microdisplays?
00:13:20 - 00:15:50
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Summary of the clip:
Is wafer bonding holding back the commercialization of ultra-bright AR/VR microdisplays?
Integrating high-efficiency RGB micro-LEDs onto silicon CMOS backplanes is the holy grail for next-generation AR and VR microdisplays, which require luminance levels exceeding 10,000 nits. Traditional manufacturing routes rely on wafer-to-wafer bonding, which requires bonding red, green, and blue epitaxial layers in three successive steps. This multi-step process introduces severe thermal stress, wafer bow, and significant material waste, as non-functional areas of the CMOS wafer are inevitably covered.
To resolve these challenges, a direct die-to-die electro-fluidic assembly approach has been developed to integrate pre-fabricated nano-LEDs directly onto CMOS substrates. By shifting the integration to a fluidic, room-temperature process, display manufacturers can completely eliminate the thermal budget issues associated with conventional epitaxial bonding. This method prevents the degradation of delicate silicon driver circuits and preserves the peak optoelectronic performance of the micro-LEDs.
This fluidic assembly method drastically reduces manufacturing costs by maximizing CMOS wafer utilization and eliminating the yield losses typically caused by wafer warp. The entire process uses stable, post-metallization materials that integrate seamlessly with existing semiconductor backend lines, offering a highly viable and cost-effective alternative to traditional wafer bonding.
In this short video, you can learn:
* The key thermal and mechanical drawbacks of using multi-step wafer bonding for RGB microdisplays.
* How direct die-to-die electro-fluidic assembly prevents CMOS driver degradation.
* The cost-saving advantages of using pre-fabricated nano-LED inks over full epitaxial wafers.
📋 **Clip Abstract** This clip compares traditional three-step epitaxial wafer bonding with a direct die-to-die fluidic assembly method for silicon-based microdisplays. By utilizing a room-temperature fluidic transfer of nano-LEDs, the proposed method bypasses thermal damage, wafer warping, and CMOS real estate waste.
#ElectroFluidicAssembly, #MicroLEDDisplays, #NanoLEDInks, #CMOSBackplanes, #ARVRMicrodisplays, #HeterogeneousIntegration
This is a highlight of the presentation:
High accuracy electrofluidic nano LED assembly for AR/VR display applications
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00:04:35 - 00:06:16
Can we achieve sub-micron pixel placement accuracy at room temperature without thermal degradation?
Can fluidic assembly of nano-LED inks finally bypass the yield and thermal limitations of mass transfer to achieve ultra-high-resolution microdisplays?
Monolithic integration of RGB micro-LEDs has long been bottlenecked by the disparate growth temperatures and lattice-matching conditions required for different semiconductor chemistries. By utilizing pre-synthesized nano-LED inks—such as indium gallium nitride for blue/green and aluminum indium arsenide for red emission—developers can optimize each material system independently on its native growth substrate. This approach decouples high-temperature epitaxial synthesis from the final display backplane, mitigating thermal budget constraints and material incompatibility.
The subsequent fluidic assembly of these nanostructures from solution onto target substrates is driven by a room-temperature electro-assembly process. Operating under mild ambient conditions, this process eliminates the thermal stresses and mechanical damage typical of conventional laser-assisted or elastomeric stamp mass transfer. The low-temperature nature of this assembly ensures complete compatibility with sensitive, large-area backplane electronics and flexible organic substrates.
This fluidic integration methodology achieves an assembly precision of approximately 1.1 micrometers in the X and Y directions, rivaling traditional top-down photolithography. Such high spatial registration enables pixel densities up to 5,000 pixels per inch (PPI), matching the resolution limits of direct wafer bonding. Furthermore, the platform supports versatile color-generation architectures, accommodating both the direct assembly of discrete RGB nano-LEDs and the integration of blue emitters with down-converting quantum dot color converters.
In this short video, you can learn:
* How nano-LED inks formulated from indium gallium nitride and aluminum indium arsenide bypass epitaxial growth incompatibilities.
* The mechanisms of a room-temperature electro-assembly process that achieves 1.1-micrometer spatial accuracy without thermal stress.
* Strategies for reaching 5,000 PPI display resolutions using both direct RGB assembly and blue emitters paired with quantum dots.
📋 **Clip Abstract** The speaker introduces a room-temperature, solution-based electro-assembly process that utilizes nano-LED inks to overcome the integration limits of high-density displays. By precisely positioning these nanostructures with 1.1-micrometer accuracy, the process achieves up to 5,000 PPI resolution using either direct RGB assembly or blue emitters combined with quantum dots.
🎤 Speaker: Jaekyun Kim
🏢 Company: Advanced View Technology Inc
📅 Event: AR/VR Connect 2025
📍 Location: Conference Centre, High Tech Campus, Eindhoven, Netherlands
🌐 Learn more at the next TechBlick event: https://www.techblick.com
#ElectroFluidicAssembly, #FluidicSelfAssembly, #NanoLEDs, #SubMicronPlacement, #MicroLEDDisplays, #HeterogeneousIntegration
00:07:38 - 00:09:26
How do you detect and verify sub-micron defect rates across millions of self-assembled pixels?
How do you detect and verify sub-micron defect rates across millions of self-assembled pixels?
As display technologies scale to 5,000 pixels per inch (PPI) for next-generation AR/VR hardware, evaluating assembly yield becomes a critical bottleneck. Conventional automated optical inspection (AOI) tools struggle with sub-micron dimensions, failing to accurately distinguish between properly aligned, misaligned, or surplus nano-LEDs. To address this, a novel fluidic assembly methodology has been developed alongside a dedicated machine learning-driven inspection system.
The electro-fluidic process successfully achieves an assembly yield of 99.97% at 5,000 PPI. By leveraging localized electrophoretic and dielectrophoretic forces, the system drives nano-LEDs into designated pixel wells while actively removing surplus or floating particles from the substrate. This results in highly precise spatial placement with a minimal alignment offset of only 0.1 micrometers.
To validate this performance at scale, the custom-built AI-based inspection system captures high-resolution surface images, dynamically extracting and labeling each assembly site. The software flags compliant assemblies with green bounding boxes in real-time, providing a scalable path for high-throughput display manufacturing. This automated feedback loop is vital for establishing high-yield production protocols for micro-LED displays.
In this short video, you can learn:
* How the electro-fluidic process achieves a 99.97% assembly yield at 5,000 PPI.
* The methodology for actively removing surplus and misplaced nano-LEDs during assembly.
* How custom computer vision algorithms automate optical inspection at sub-micron scales.
📋 **Clip Abstract** The speaker demonstrates a high-yield electro-fluidic assembly process that achieves 99.97% alignment accuracy at 5,000 PPI with a 0.1-micrometer spatial offset. He also introduces an in-house machine learning-based automated optical inspection system designed to verify and label individual nano-LED placement.
#ElectroFluidicAssembly, #DielectrophoreticAssembly, #SubMicronAOI, #NanoLEDs, #MicroLEDDisplays, #AugmentedRealityDisplays