MicroLED Integration via Fluidic Self-Assembly: Chemistry Meets Design

MicroLED Integration via Fluidic Self-Assembly: Chemistry Meets Design | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Physical Sciences - Article MicroLED Integration via Fluidic Self-Assembly: Chemistry Meets Design Heiko Jacobs, Alper Soydan, Nishchay Isaac, Guru Kambala, Christoph Baumer, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8990492/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Next-generation semiconductor technologies increasingly demand massively parallel assembly methods that can integrate discrete microscopic chiplets with high throughput, precision, and scalability 1,2 . Fluidic self-assembly (FSA) 3 has emerged as a powerful candidate for parallel integration 4 , yet its application has remained limited to chiplets larger than several tens of micrometers. Here, we present the FSA of microscopic light-emitting diodes (microLEDs) onto molten solder-based receptor arrays, where the chiplets attach, self-align, and form electrical connections autonomously until all receptors are occupied. MicroLEDs with dimensions of 18 × 18 × 2 µm 3 are assembled with a 99.77% yield and at rates exceeding 12,000 chiplets per minute. These metrics push the FSA into the deep microscale by achieving dimensions five and twelve times smaller in area and volume, respectively, than previous records 5 . Three mutually necessary criteria define the operational window for high-yield assembly, each addressing a distinct challenge inherent to this scale. First, a mobile slurry of chiplets maximizes efficient chiplet-receptor interaction across the solder bumps. Second, precisely tuned acid concentration in the fluidic transfer medium enables reliable solder wetting and attachment. Third, a 20-fold suppression of oxidation is essential, as oxide growth kinetics increasingly outcompete solder wetting at the microscale. Device functionality is validated through a self-assembled microLED display with a transparent top electrode. Ultimately, these results demonstrate massively parallel assembly of truly microscopic chiplets at scales previously inaccessible, opening new pathways for emerging photonic and semiconductor integration technologies. Physical sciences/Engineering/Electrical and electronic engineering Physical sciences/Materials science/Materials for devices/Electronic devices Physical sciences/Chemistry/Surface chemistry/Surface assembly Physical sciences/Optics and photonics/Lasers, LEDs and light sources/Inorganic LEDs Physical sciences/Engineering/Electrical and electronic engineering Physical sciences/Materials science/Materials for devices/Electronic devices Physical sciences/Chemistry/Surface chemistry/Surface assembly Physical sciences/Optics and photonics/Lasers, LEDs and light sources/Inorganic LEDs Full Text Additional Declarations There is NO Competing Interest. Supplementary Files SupplementaryVideo1SolderDispensing.mp4 Solder Dispense Coating Technique SupplementaryVideo2FSA.mp4 Fluidic Self-Assembly Process SupplementaryVideo3MicroLEDSelectiveLighting.mp4 Testing and Lighting up of a MicroLED Display Segment Cite Share Download PDF Status: Under Review Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8990492","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":602892831,"identity":"08ffac5e-7270-4994-a188-2dbb12cc6540","order_by":0,"name":"Heiko 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First, a mobile slurry of chiplets maximizes efficient chiplet-receptor interaction across the solder bumps. Second, precisely tuned acid concentration in the fluidic transfer medium enables reliable solder wetting and attachment. Third, a 20-fold suppression of oxidation is essential, as oxide growth kinetics increasingly outcompete solder wetting at the microscale. Device functionality is validated through a self-assembled microLED display with a transparent top electrode. 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