Art Dobie | MicroScreen LLC: Why must you avoid coating the squeegee side of a screen with release agents when printing electronic inks?
00:06:55.888 - 00:08:32.848
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Summary of the clip:
Why must you avoid coating the squeegee side of a screen with release agents when printing electronic inks?
Evaluating the impact of a nano-scale surface treatment on screen printing requires a rigorous experimental design to isolate chemical release properties from mechanical press variables. By applying the nano treatment to alternating corners of a four-up layout, researchers can compare treated and untreated prints on the exact same sheet. This clever spatial design eliminates common process noises, such as an unlevel squeegee or platen, which would otherwise skew the comparison.
The application of the nano-treatment must target not just the polyester or stainless steel mesh wires, but also the vertical sidewalls of the photo-formed stencil emulsion. Cohesive ink release depends strongly on reducing adhesive forces at these boundaries, especially in thicker emulsion over mesh (EOM) designs. Achieving a uniform, ultrathin nanometer-scale coating ensures that the open area of the stencil is not physically restricted, keeping the screen's nominal volume intact.
However, process engineers must carefully avoid applying the slip agent to the squeegee side of the screen. Some degree of friction is fundamentally necessary on the top surface of the mesh to ensure that the paste rolls properly in front of the squeegee blade. Without this friction, the paste simply slides across the screen surface like a solid block, preventing the critical shearing action required to drop the paste's viscosity and fill the cavities.
In this short video, you can learn:
* How to design a spatial control layout on a single printing screen to eliminate squeegee leveling bias.
* The importance of coating emulsion sidewalls alongside mesh wires for complete deposit release.
* Why top-side squeegee friction must be preserved to maintain correct paste rolling and shearing dynamics.
π **Clip Abstract** This clip details the experimental control method of using an alternating corner array to isolate the effects of a nano surface treatment from squeegee or platen leveling issues. Art also highlights the crucial balance of maintaining squeegee-side friction to prevent ink sliding and preserve the paste's necessary shear-rolling dynamics.
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#ScreenPrinting, #PasteRheology, #StencilEmulsion, #SqueegeeDynamics, #PrintedElectronics, #AdditiveElectronics
This is a highlight of the presentation:
Effect of Hydrophobic/Oleophobic Nano Surface Treatment on the Release of Resistive PTC carbon paste from Emulsion Screens for Screen-Printed Heater Applications
Future of Electronics RESHAPED USA 2026
10-11 June 2026
Computer History Museum, Mountain View, California, USA
Organised By:
TechBlick
More Highlights from the same talk.
00:02:02.100 - 00:04:02.220
How can we bypass the physical constraints of screen printing to deliver thicker deposits of high-viscosity pastes?
How can we bypass the physical constraints of screen printing to deliver thicker deposits of high-viscosity pastes?
The physics of off-contact screen printing limits the wet-film deposit thickness to the theoretical volume of the open mesh and emulsion. During the print stroke, the squeegee creates a transient line of contact, turning the screen cavity and the substrate beneath it into a closed, four-sided mold. Once the squeegee passes, the tension of the mesh pulls the screen upward, requiring the paste to cleanly release from the mesh wires and photo-formed emulsion sidewalls.
To overcome the physical release limitations of highly viscous, functional pastes, printers must exploit the pseudoplastic rheology of the material. As the squeegee moves and shears the ink, the viscosity of the pseudoplastic paste drops dramatically, allowing it to flow. By introducing a nano-scale surface release agent inside the print cavities, the boundary layer friction is reduced, allowing the sheared paste to slide out of the screen more efficiently.
This technique allows manufacturing engineers to "cheat" the standard aspect ratio limitations of screen printing without altering the bulk paste chemistry. Improving this release behavior is highly critical in applications like printed solar cells, where narrow, high-aspect-ratio grid lines are required, as well as in printed electronics where uniform deposition translates directly to optimal electrical performance.
In this short video, you can learn:
* How off-contact screen tension acts as a dynamic four-sided mold during the print stroke.
* Why pseudoplastic rheology and shear-thinning behavior are vital to filling and emptying mesh cavities.
* How nano surface treatments act as slip agents to increase functional ink deposition per squeegee stroke.
π **Clip Abstract** Art Dobie explains the mechanics of off-contact screen printing, detailing how mesh tension and squeegee motion form a temporary four-sided mold. He proposes using nano surface treatments inside the screen cavities to manipulate the shear-thinning behavior of pseudoplastic pastes for enhanced deposition.
Link in comments π
#ScreenPrinting, #PseudoplasticRheology, #NanoSurfaceTreatments, #HighAspectRatioPrinting, #PrintedElectronics, #PrintedPhotovoltaics
00:11:57.808 - 00:13:55.084
Can a simple nano-treatment on a printing screen slash heater circuit response times by nearly 30%?
Can a simple nano-treatment on a printing screen slash heater circuit response times by nearly 30%?
The physical addition of a nano release agent on the screen results in measurable, high-value improvements in the final cured film characteristics of PTC carbon inks. Without changing any print parameters or altering the ink formulation, the treated screen sections yielded a cured deposition that was approximately 3% thicker. This directly correlates to better cavity emptying and a higher volume of functional material transferring to the PET substrate.
This increased deposition thickness yields a cascading set of improvements in electrical performance. Due to the thicker cross-section of the printed carbon tiles, the non-powered electrical resistance of the printed circuits dropped by 9.8%. Consequently, when powered under identical conditions, the printed heater element achieved a 7% higher average maximum temperature compared to the untreated control.
Most significantly, the transient thermal performance of the printed heater was dramatically accelerated. In "zero-to-60" style thermal ramp tests, the elements printed with the treated screen reached target operating temperatures 28% faster while utilizing less overall current. This demonstrates how minor surface-level modifications of screen printing stencils can significantly optimize the energy efficiency and response times of printed electronic components.
In this short video, you can learn:
* How a nano release agent produces a 3% increase in cured film thickness under identical press settings.
* The quantitative relationships between increased deposition thickness, reduced resistance, and thermal efficiency.
* Why screen surface modification can reduce thermal response times by 28% while lowering current consumption.
π **Clip Abstract** Art Dobie presents the quantitative results of using a nano-treated screen for printing PTC carbon heater elements, demonstrating a 3% increase in cured thickness and a 9.8% drop in resistance. These physical changes translate directly into thermal performance gains, accelerating heat ramp times by 28% at lower current draws.
Link in comments π
#NanoReleaseAgent, #PTCCarbonInk, #PrintedHeaters, #ScreenPrinting, #FlexibleElectronics, #ThermalManagement