Denis Cormier | Rochester Institute of Technology: How does the conductivity of the printed copper traces compare to that of bulk copper, and what are the implications of the large cross-sectional areas?
00:08:34 - 00:08:44
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Summary of the clip:
How does the conductivity of the printed copper traces compare to that of bulk copper, and what are the implications of the large cross-sectional areas?
The speaker emphasizes the achievement of matching the conductivity of bulk copper in the printed traces. This is a significant result, indicating the high quality and density of the printed metal. The key factor contributing to this high conductivity is the formation of solid core copper wires, achieved through the molten metal jetting process.
The speaker highlights the large cross-sectional areas of the printed traces, emphasizing that these are not thin films or micron-scale features. Instead, the process creates substantial, solid metal lines with aspect ratios approaching one-to-one. This allows for the application of standard current carrying capacity tables to determine the safe current limits for these printed wires.
The ability to print solid core copper wires with bulk-like conductivity opens up opportunities for power distribution and other high-current applications. The speaker notes that the standoff distance of 15 millimeters during printing also allows for the potential to follow contours on non-planar surfaces, although this has not yet been fully explored due to the lack of a five-axis motion stage.
In this short video, you can learn:
* The achievement of matching bulk copper conductivity in printed traces.
* The significance of large cross-sectional areas and solid core wire formation.
* The implications for high-current applications and potential for non-planar printing.
š **Clip Abstract** This segment focuses on the high conductivity achieved in the printed copper traces, comparable to bulk copper, and the implications of the large, solid cross-sections for high-current applications.
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#BulkCopperConductivity, #MoltenMetalJetting, #SolidCoreCopper, #HighCurrentTraces, #SemiconductorPackaging, #PowerElectronics
This is a highlight of the presentation:
On-Demand Jetting of Molten Metal Droplets for Power Electronics Applications
More Highlights from the same talk.
00:01:09 - 00:02:40
Can We 3D-Print Solid Core Metal Traces Without Nanoparticles or Sintering?
Can We 3D-Print Solid Core Metal Traces Without Nanoparticles or Sintering?
Printed electronics typically rely on metal nanoparticle inks that require post-deposition drying, curing, and sintering to achieve electrical conductivity. This clip introduces an alternative approach that melts bulk metal wire directly within a miniature crucible and ejects molten droplets on demand using magneto hydrodynamic (MHD) jetting.
By leveraging MHD physics, the system acts as a molten metal inkjet printer. Instead of sintering fragile nanoparticles, the droplets solidify immediately upon landing on the substrate, creating high-purity, solid core metal traces with bulk-like electrical properties.
This technique, originally developed for aerospace-grade metal additive manufacturing, is now being adapted for printed electronics. By bypassing the chemical constraints of inks, it opens up a new paradigm of printing solid wire structures directly onto diverse substrates.
In this short video, you can learn:
* How magneto hydrodynamic (MHD) jetting utilizes electromagnetic fields to eject molten metal droplets on demand.
* Why bulk metal wire feedstock provides a low-cost, chemically stable alternative to traditional nanoparticle inks.
* The mechanical and structural transition of molten droplets as they cool down and solidify into solid metal lines.
š **Clip Abstract** [Professor Denis Cormier introduces Magneto Hydrodynamic (MHD) jetting, a technique that melts bulk metal wire to print solid core traces without sintering or curing. Originally developed for 3D printing aerospace parts, this process offers a low-cost, high-conductivity alternative to nanoparticle-based printed electronics.]
#MHDJetting, #MoltenMetalJetting, #SinterlessPrinting, #BulkWireFeedstock, #AdditiveElectronics, #PrintedElectronics
00:09:19 - 00:10:59
Why Are Your 3D-Printed Metal Traces Exploding into Bubbles?
Why Are Your 3D-Printed Metal Traces Exploding into Bubbles?
When jetting high-temperature molten metal onto polymeric substrates like Kapton, unexpected structural defects can severely compromise trace integrity. This segment investigates the mystery of microscopic pinholes and large void bubbles discovered during cross-sectional analysis of printed aluminum lines.
The root cause of these voids is trace atmospheric moisture absorbed by the Kapton film. When the molten metal hits the damp polymer, the moisture vaporizes instantly, blowing steam bubbles into the solidifying metal trace and leaving micro-voids that initiate fatigue cracks under physical flexing.
By implementing a pre-drying step for the substrate, these pinholes are eliminated, ensuring high metallurgical density. Impressively, even with some micro-voids, the underlying metal maintains bulk-level conductivity, allowing printed traces to carry currents exceeding 10 Amps.
In this short video, you can learn:
* How atmospheric moisture absorption in Kapton films causes outgassing and void formation during high-temperature metal printing.
* The critical impact of microscopic pinholes on the mechanical fatigue life of printed traces subjected to flexing.
* Why metallurgical density and bulk conductivity are vital to running high-current applications (over 10 Amps) through printed electronic lines.
š **Clip Abstract** [Professor Cormier diagnoses a common failure mode in printed electronics where moisture-induced outgassing on Kapton substrates creates void bubbles and pinholes in molten metal traces. He demonstrates how substrate pre-drying eliminates these defects, restoring mechanical fatigue resistance and enabling currents up to 10 Amps.]
#MoltenMetalJetting, #PolyimideOutgassing, #SubstratePreDrying, #HighCurrentPrintedTraces, #AdditiveElectronics, #FlexibleElectronics
00:03:40 - 00:05:03
Is the Era of Expensive Nanoparticle Silver Inks Dead?
Is the Era of Expensive Nanoparticle Silver Inks Dead?
Nanoparticle silver and copper inks are notoriously expensive and require energy-intensive photonic or thermal curing to become conductive. This segment analyzes the commercial and technical benefits of direct molten wire jetting, where a kilogram of raw copper wire costs a fraction of nanoparticle alternatives.
By printing solid-core metal wires directly from molten feedstocks, the traces achieve identical electrical conductivity to bulk metal without any drying, curing, or post-cleaning steps. However, processing molten metals introduces serious fluid dynamic challenges, particularly when scaling down features.
Currently, the process is limited to a minimum nozzle diameter of 150 microns. Transitioning to smaller, high-resolution traces requires significantly higher energy to overcome surface tension and viscous forces when pushing molten metal through micro-scale orifices.
In this short video, you can learn:
* The cost-comparison of raw metal wire feedstocks (around $30-$35 per kilogram) versus highly engineered nanoparticle formulations.
* Why direct solidification yields bulk conductivity immediately without thermal, chemical, or photonic sintering.
* The rheological and energetic limitations that currently constrain the minimum nozzle diameter of molten metal jets.
š **Clip Abstract** [This clip evaluates the economics and physical limitations of molten metal jetting, highlighting its massive cost advantage over nanoparticle inks and its ability to achieve bulk metal conductivity without sintering. However, the speaker outlines the fluid dynamic constraints that currently limit nozzle diameters to a minimum of 150 microns.]
#MoltenMetalJetting, #ConductiveInks, #SinterlessPrinting, #RheologicalConstraints, #PrintedElectronics, #AdditiveElectronics