Alexander Goerk | Hamamatsu Photonics: Is it possible to sinter copper nanoparticle inks in a standard atmosphere without an inert gas purge?

How do you sinter conductive inks on heat-sensitive plastics without melting the substrate?

This clip details two distinct laser irradiation approaches for post-processing printed electronics: spot irradiation and line scan optics. The spot approach requires a vision system to precisely target and scan individual conductive traces, making it suitable for complex layouts or R&D. In contrast, the line scan approach irradiates a wide, constant line, which is ideal for upscaling to high-throughput, roll-to-roll manufacturing as it processes the entire width of the web simultaneously.

The core technical advantage lies in the principle of selective heating, enabled by the 940 nm near-infrared wavelength of the diode laser. This specific wavelength is strongly absorbed by the metallic particles within the conductive ink but is largely transparent to common flexible substrates like PET, PI, or glass. This critical difference in absorption characteristics is the key to the process's success.

As a result, thermal energy is generated and concentrated exclusively within the printed ink traces, not in the surrounding substrate. This allows the ink to reach the high temperatures required for sintering and achieving high conductivity in milliseconds, while the bulk substrate remains cool and undamaged. This method provides a rapid, energy-efficient, and non-contact solution for creating robust conductive patterns on thermally sensitive materials.

In this short video, you can learn:
* The difference between spot and line scan laser optics for printed electronics.
* The principle of selective heating using a 940 nm wavelength.
* How to achieve high-speed sintering on flexible substrates without thermal damage.
📋 **Clip Abstract** This clip explains how Hamamatsu's 940 nm diode lasers enable selective sintering of conductive inks on thermally sensitive substrates like PET. It contrasts spot and line scan approaches, highlighting the latter's suitability for high-volume, roll-to-roll manufacturing.
🔗 Link in comments 👇

What if your laser could not only process your material but also measure its temperature in real-time?

A key enabling feature for robust laser processing is the ability to monitor the process in-situ. This clip introduces an advanced capability integrated into the laser system: real-time temperature measurement of the processing surface. This is not achieved with an external pyrometer but is done coaxially, using the very same optics that deliver the laser beam to the workpiece.

This integrated approach ensures that the temperature is measured at the exact point of laser interaction, providing highly accurate and instantaneous thermal feedback. Access to this real-time thermal information is invaluable for process development, allowing scientists and engineers to precisely evaluate and understand the material's response to the laser energy. It is the key to defining a stable and repeatable process window.

For production, this feature enables powerful process control. The temperature data can be fed into a closed-loop control system that automatically adjusts the laser's output power to maintain a constant, stable surface temperature. This compensates for variations in material absorption or processing speed, ensuring consistent quality and high yields, which is critical for scaling to high-volume manufacturing.

In this short video, you can learn:
* How to measure surface temperature coaxially with the processing laser beam.
* The importance of real-time thermal data for process evaluation and control.
* How closed-loop temperature control can stabilize laser processes for high-yield manufacturing.
📋 **Clip Abstract** Discover a key feature of Hamamatsu's laser systems: the ability to measure the processing surface temperature in real-time through the same optics. This enables precise process evaluation and closed-loop power control to maintain stable conditions, ensuring high-quality, repeatable results.
🔗 Link in comments 👇