Jan Gülink | QubeDot: Why is pick-and-place obsolete for high-resolution microLED displays?
00:13:18 - 00:15:12
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Why is pick-and-place obsolete for high-resolution microLED displays?
Manufacturing a standard 4K display requires assembling approximately 25 million individual microLEDs. Even with a theoretical transfer yield of 99.99%, a display would still suffer from over 2,400 dead pixels, posing severe repair and redundancy challenges. Traditional pick-and-place equipment operating at 100,000 components per hour would take roughly ten days to build a single display, making high-throughput parallel transfer a commercial necessity.
To address this bottleneck, laser-induced forward transfer (LIFT) is emerging as a critical enablement technology. LIFT enables massive parallel assembly, reaching transfer rates of up to 130 million components per hour. This laser-based method decouples transfer speeds from mechanical placement limits, making mass production economically viable.
In addition to high transfer rates, successful assembly requires robust metallurgical bonding. QubeDot couples LIFT and laser lift-off (LLO) workflows with fine-pitch indium deposition. This process ensures reliable electrical and mechanical micro-bonding between the transferred microLEDs and the underlying backplane.
In this short video, you can learn:
* Why a 99.99% transfer yield still leaves thousands of dead pixels on a standard 4K microLED display.
* How laser-induced forward transfer (LIFT) achieves throughputs of over 130 million units per hour.
* The role of fine-pitch indium deposition and laser lift-off (LLO) in achieving robust micro-scale bonds.
📋 **Clip Abstract**
Jan Gülink analyzes the mathematical bottleneck of transfer yields in high-resolution microLED displays and evaluates why traditional pick-and-place fails. He presents Laser-Induced Forward Transfer (LIFT) as a high-throughput solution capable of transferring 130 million devices per hour.
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#LaserInducedForwardTransfer, #LaserLiftOff, #FinePitchIndium, #MassTransfer, #MicroLEDDisplays, #DisplayManufacturing
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00:08:01 - 00:09:17
Can native InGaN solve the microLED red efficiency bottleneck?
Can native InGaN solve the microLED red efficiency bottleneck?
Monolithic integration of RGB microLEDs is often hindered by the material mismatch between AlInGaP (traditionally used for red) and InGaN (used for blue and green). QubeDot addresses this by developing a native red InGaN technology. This approach allows the entire RGB spectrum to be processed within a single material system, simplifying manufacturing and backend integration.
One critical characteristic of native InGaN red emitters is their high sensitivity to injection current density, which causes a blueshift in emission wavelength. Managing this shift requires precise current control or specialized driving schemes to maintain color stability. Additionally, this platform enables high-resolution designs with features down to three microns, opening up opportunities for highly customized pixel shapes and variable aspect ratios.
By moving away from standard square pixels, designers can adapt microLED layouts directly to specific customer requirements on the wafer level. This flexibility is vital for specialized optical setups, custom projection systems, and advanced near-eye displays.
In this short video, you can learn:
* How native InGaN red microLEDs exhibit wavelength shifts dependent on current density.
* The feasibility of microLED feature sizes down to three microns with custom aspect ratios.
* The design freedom of separating emitters on a single chip versus distinct wafer-level components.
📋 **Clip Abstract**
Jan Gülink highlights QubeDot's native InGaN red microLED technology and its tuning behavior under varying current densities. He demonstrates the platform's capability to process sub-three-micron features with customizable geometries tailored for specialized display applications.
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#RedInGaN, #MonolithicRGB, #WavelengthBlueshift, #SubThreeMicronPixels, #MicroLEDDisplays, #NearEyeDisplays
00:12:00 - 00:13:16
Does scaling microLEDs below one micron inevitably kill efficiency?
Does scaling microLEDs below one micron inevitably kill efficiency?
As microLEDs scale down to single-digit micron dimensions, their efficiency typically drops due to non-radiative recombination at open sidewall defects. This phenomenon is modeled by modifying the Shockley-Read-Hall (A) term in the ABC model to account for the surface-to-volume ratio. However, experimental data shows that internal quantum efficiency (IQE) remains high until the device diameter scales below one micrometer.
Maintaining high efficiency at small scales requires precise sidewall passivation and post-mesa etch treatments. QubeDot utilizes specialized wet etching conditions using potassium hydroxide (KOH) or tetramethylammonium hydroxide (TMAH) following dry etching steps. This chemical treatment removes dry-etch-induced physical damage, exposing clean crystal facets and reducing surface defect density.
Following the wet etch restoration, PECVD-deposited passivation layers protect the clean surfaces. This process pipeline ensures that microLEDs retain excellent electrical and optical performance even when pixel dimensions are scaled down aggressively.
In this short video, you can learn:
* Why internal quantum efficiency (IQE) only drops significantly when microLED dimensions fall below one micron.
* How KOH and TMAH wet chemical etching repairs dry-etch crystal damage to restore sidewall quality.
* The role of PECVD preservation layers in maintaining stable external quantum efficiency.
📋 **Clip Abstract**
Jan Gülink explains how careful post-dry-etch wet chemical treatments using KOH or TMAH can prevent microLED efficiency loss at small scales. He shows that by removing sidewall damage down to clean crystal facets, high IQE can be sustained down to one-micron dimensions.
🔗 Link in comments 👇
#SubMicronMicroLED, #SidewallPassivation, #KOHWetEtch, #ShockleyReadHall, #MicroLEDDisplays, #ARLightEngines