Brandon Peters | Nagase ChemteX: How does a minor solvent modification unlock the bottleneck from 75-micron to 50-micron ultra-fine screen printing?
11:49 - 13:00
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Summary of the clip:
How does a minor solvent modification unlock the bottleneck from 75-micron to 50-micron ultra-fine screen printing?
Shrinking printed trace widths from 75 microns down to the ultra-fine 50-micron regime introduces severe paste transfer bottlenecks. Standard conductive inks suffer from localized voids and incomplete line transfers due to excessive paste viscosity and capillary pinning within the tiny screen apertures. To overcome this, the physical and thermodynamic properties of the ink must be precisely tuned.
By retaining the core binder and advanced deagglomeration process of the successful ITO-compatible formulation but substituting the solvent, the 126 variant was developed. This solvent substitution strategically lowers the paste viscosity, enhancing flow through the ultra-fine 400-mesh stainless steel screen. Simultaneously, it adjusts the surface tension of the ink to match the wetting envelope of ITO-coated PET.
The result of this micro-formulation shift is the successful, defect-free printing of 56-micron traces with 46-micron gaps. However, this high-performance formulation is highly substrate-specific; printing the same ink on standard PET results in a continuous, merged mass. This highlights that as print dimensions shrink, the printability window narrows, requiring co-design of ink rheology and substrate chemistry.
In this short video, you can learn:
* The physical transfer limitations and voiding issues associated with screen printing sub-50-micron traces.
* How solvent selection simultaneously moderates paste viscosity and tunes ink surface tension for micro-apertures.
* The narrow operating window of ultra-fine line inks, rendering them highly substrate-specific.
📋 **Clip Abstract** This clip highlights the transition from 75-micron to 50-micron ultra-fine line printing on ITO-coated substrates. The speaker demonstrates how swapping the solvent vehicle optimizes viscosity and surface tension to achieve clean 56-micron traces.
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#UltraFineScreenPrinting, #InkRheology, #ITOCoatedPET, #MicroAperturePrinting, #PrintedElectronics, #FlexibleElectronics
This is a highlight of the presentation:
Future of Electronics RESHAPED USA 2026
Computer History Museum, Mountain View, California, USA
Organised By:
TechBlick
More Highlights from the same talk.
05:44 - 07:33
Why does screen printing ultra-fine conductive traces randomly fail with teeth and bridging defects?
Why does screen printing ultra-fine conductive traces randomly fail with teeth and bridging defects?
Transitioning to ultra-fine line screen printing introduces complex hydrodynamic and rheological challenges that manifest as localized defects. Two of the most notorious defects are bridging, which is the random connection of adjacent traces, and teeth, which are spiky protrusions extending perpendicular to the print stroke direction. These issues are highly sensitive to print direction, typically concentrating where the squeegee stroke terminates on traces parallel to the squeegee.
Resolving these micro-defects requires systematic optimization of key press parameters rather than simple paste reformulation. Softening the squeegee durometer to 70A provides a more conformable edge that prevents paste from bleeding underneath the emulsion, directly eliminating teeth defects. Meanwhile, increasing the off-contact distance ensures a clean, snappy screen release from the substrate, mitigating paste drag and bridging.
To compensate for the elevated off-contact distance, squeegee pressure must be slightly increased to maintain effective paste transfer through high-mesh counts. Additionally, reducing the squeegee speed allows the shear-thinning conductive paste sufficient time to wet the substrate uniformly, smoothing out line waviness without causing slumping.
In this short video, you can learn:
* The mechanical root causes of bridging and spiky tooth-like defects in fine-line screen printing.
* How squeegee durometer selection directly impacts the elimination of teeth defects.
* The multi-variable interplay of off-contact distance, squeegee speed, and pressure for yield optimization.
📋 **Clip Abstract** This clip details the diagnostics and mechanical optimization steps required to eliminate print defects like teeth and bridging in sub-100-micron traces. By adjusting squeegee durometer, off-contact distance, and speed, the researcher achieves ultra-clean line definition on high-mesh screens.
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#FineLineScreenPrinting, #ConductiveTraces, #SqueegeeDurometer, #ShearThinningPaste, #PrintedElectronics, #FlexibleElectronics
09:26 - 11:47
Can you use the exact same conductive ink for PET and ITO-coated PET, or does surface energy break your yield?
Can you use the exact same conductive ink for PET and ITO-coated PET, or does surface energy break your yield?
When transitioning conductive pastes from standard PET to indium tin oxide coated PET, the drastic difference in surface energy alters wet-out behavior. High surface energy substrates like ITO can cause severe surface energy mismatches, resulting in pinholes and circular voids throughout the printed trace. This phenomenon demonstrates that high-resolution inks must be optimized specifically for the chemical interface of the substrate.
Standard adjustments to medium chemistry and filler loading often fail to resolve these wetting discrepancies or can introduce high resistivity. Instead, advanced deagglomeration processing techniques are required to properly disperse fine silver fillers in compatible vehicle mediums. This micro-scale dispersion control prevents clogging in 75-micron channels while maintaining superb electrical conductivity.
Through systematic process modifications, Nagase ChemteX engineered the 688-125 formulation specifically for ITO-coated substrates. This ink achieves a remarkably low sheet resistance of 9 milliohms per square per mil while maintaining precise 75-micron trace and gap profiles. Conversely, the optimal formulation for bare PET exhibits poor compatibility on ITO, confirming the necessity of substrate-specific ink design.
In this short video, you can learn:
* The role of surface energy mismatches in creating circular voids and pinholes in printed traces.
* Why standard paste reformulations fail on ITO-coated PET without advanced filler deagglomeration processes.
* The technical divergence of designing separate, substrate-specific inks for bare PET versus ITO.
📋 **Clip Abstract** The speaker explains how high-surface-energy ITO substrates cause surface energy mismatches and voids when using standard PET conductive inks. He presents a newly processed paste formulation that achieves a low resistivity of 9 mOhm/sq/mil on ITO.
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#ConductiveInks, #ITOCoatedPET, #FillerDeagglomeration, #SurfaceEnergyMismatch, #PrintedElectronics, #FlexibleElectronics