Chisato Oyama | Komori Corp: Is Multi-Layer Printed Silver the Ultimate Solution for Sub-30-Micron MicroLED Bonding?
00:11:15.600 - 00:12:48.400
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Summary of the clip:
How can gravure offset printing overcome the registration and aspect ratio limits of conventional additive manufacturing for ultra-fine-pitch semiconductor packaging?
Achieving the high aspect ratios required for advanced semiconductor packaging demands unprecedented precision in multi-pass additive deposition. Utilizing gravure offset printing to perform sequential, high-accuracy overprinting of seven to ten layers of silver paste in identical spatial coordinates allows manufacturers to construct robust, highly defined conductive silver bumps. This precise layer-on-layer registration enables the fabrication of high-density interconnects without the slump or lateral spreading typical of conventional thick-film paste deposition.
The integration of these printed micro-bumps into flexible hybrid electronics (FHE) has been validated through high-profile industry collaborations, including the fabrication of flexible Arduino prototypes. By printing mounting bumps directly onto conductive traces with line widths and pitches scaled down to 30 microns and 60 microns, this method proves its viability for commercial-grade flexible systems. This demonstrates that gravure offset technology can successfully bridge the gap between traditional silicon-based components and flexible polymeric substrates.
Pushing the boundaries of ultra-fine-pitch assembly, this additive technique has successfully achieved bare IC chip mounting at a 28-micron pitch with 15-micron line widths. Cross-sectional and back-view analyses confirm that all printed silver bumps establish reliable, void-free electrical connections with corresponding gold chip pads and underlying traces. This capability offers a high-throughput, cost-effective alternative to conventional thermo-compression bonding and micro-bumping processes for next-generation packaging.
In this short video, you can learn:
* How multi-layer gravure offset overprinting achieves high-aspect-ratio silver bumps with precise spatial registration.
* The application of printed silver bumps in flexible hybrid electronics, featuring functional flexible Arduino devices.
* The technical parameters and connectivity results of mounting bare IC chips on printed bumps at a 28-micron pitch.
π **Clip Abstract** The speaker discusses the fabrication of multi-layer printed silver bumps using gravure offset printing for flexible hybrid electronics and fine-pitch IC mounting. Technical achievements include successful bare chip integration on printed bumps at pitches down to 28 microns with reliable connectivity to gold pads.
π€ Speaker: Chisato Oyama
π’ Company: Komori Corp
π
Event: Mini- & Micro-LED Displays 2022: Markets, Manufacturing Innovations, Applications, Promising Start-ups
π Location: TechBlick Platform |Online
π Learn more at the next TechBlick event: https://www.techblick.com
#PrintedSilverBumps, #MicroLEDBonding, #FinePitchInterconnect, #HighAspectRatioPrinting, #AdvancedPackaging, #MicroLEDDisplays
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00:03:31.500 - 00:05:16.000
Can Gravure Offset Printing Overcome the Limits of Screen Printing for Sub-10-Micron Electronics?
How can printed electronics manufacturers achieve sub-micron positional accuracy alongside ultra-fine line resolution without compromising throughput?
The answer lies in the mechanical precision of gravure offset printing, a three-stage transfer process engineered for high-fidelity patterning. The sequence begins with a doctor blade filling a micro-patterned gravure plate with functional paste, followed by a rolling silicone blanket that lifts the paste from the plate. In the final phase, this elastomeric blanket transfers the complete pattern onto the target substrate, leveraging controlled surface energy differentials to ensure clean release.
By maintaining continuous, synchronized contact between the gravure plate, the transfer blanket, and the substrate, this method inherently minimizes registration drift and spatial distortion. This mechanical configuration eliminates the positioning gaps common in alternative deposition methods, making it an ideal candidate for multi-layer electronic device fabrication. The resulting high positional precision allows for the reliable alignment of fine-line features over large areas.
Achieving stable, high-definition printed features requires a holistic optimization of the entire deposition ecosystem. Success depends on the precise calibration of the printing system, the rheological properties of the functional paste, the surface chemistry of the silicone blanket, and the micro-topography of the gravure plate. When these variables are harmonized, the system delivers highly repeatable, high-resolution conductive traces suitable for advanced circuitry.
In this short video, you can learn:
* The step-by-step mechanical sequence of the gravure offset printing process.
* How synchronized contact minimizes positioning gaps to deliver high positional precision.
* The critical system variables required to optimize and stabilize high-definition printing.
π **Clip Abstract** The speaker explains the fundamental mechanism of gravure offset printing, detailing how a doctor blade, gravure plate, and silicone blanket transfer paste to a substrate. The presentation highlights the process's key advantages in positional precision and high-definition stability, supported by a video demonstration of the printing sequence.
π€ Speaker: Chisato Oyama
π’ Company: Komori Corp
π
Event: Mini- & Micro-LED Displays 2022: Markets, Manufacturing Innovations, Applications, Promising Start-ups
π Location: TechBlick Platform |Online
π Learn more at the next TechBlick event: https://www.techblick.com
#GravureOffsetPrinting, #SubTenMicron, #SiliconeBlanketTransfer, #PasteRheology, #PrintedElectronics, #AdditiveElectronics
00:08:14.500 - 00:09:41.900
How Do We Print Sub-10 Micron Solder Bumps for Next-Generation MicroLED Integration?
How Do We Print Sub-10 Micron Solder Bumps for Next-Generation MicroLED Integration?
Integrating microLEDs requires printing solder bumps at pitches and dimensions far below conventional surface-mount technology (SMT) capabilities. Using Type 9 fine-particle solder pastes, gravure offset printing has successfully achieved dot arrays with diameters as small as 6 microns. This allows display manufacturers to deposit uniform interconnect sites across a full 300mm wafer footprint.
To prevent bridging while ensuring sufficient vertical volume for reliable joints, aspect ratio engineering is critical. By taking advantage of high-precision registration, developers can overprint the same site multiple times to stack the solder paste. This increases bump height to 4 microns for micro-scale dots, and up to 30 microns for larger features, significantly improving the mechanical and electrical robustness of the contact.
The scaling of solder paste to sub-10-micron sizes requires meticulous control over metal load and solvent evaporation rates. As the feature size shrinks, the surface area-to-volume ratio increases, meaning any instability in the paste can cause transfer failures or incomplete wetting during reflow. Layer-by-layer stacked printing offers a robust path to overcome these rheological limitations and achieve stable micro-junctions.
In this short video, you can learn:
* Realizing 6-micron to 20-micron solder dot patterns using Type 9 solder paste
* Stacked multi-pass printing to control bump aspect ratio and vertical height
* The challenges of managing fine-particle solder rheology for 300mm wafer-scale microLED packaging
π **Clip Abstract** This clip details the successful printing of Type 9 solder paste dots down to 6 microns for microLED and semiconductor packaging. It explains how multi-pass overprinting is used to increase the aspect ratio and height of micro-solder bumps.
#GravureOffsetPrinting, #Type9SolderPaste, #StackedMultiPassPrinting, #MicroSolderBumps, #MicroLEDPackaging, #AdvancedPackaging