MLT utilizes both Coherent and nLIGHT ultrafast, picosecond lasers to produce sharp, clean edges. The Coherent picosecond laser is capable of generating 1064nm or 532nm wavelengths at 200KHz. The integration of nLIGHT’s helix pulsed fiber laser allows for configurable pulse widths from 50ps to 400ps and a user selectable repetition rate from 50KHz to 10MHz.
Advancing Laser Micro-processing for Displays, Solar, and Medical Devices:
Displays & OLEDs
Processing of thin and ultra-thin glass displays and OLEDs is becoming more important in display manufacturing. Patterning OLEDs (organic light emitting diodes) are used for displays from tablets to flat screens. Ultrafast laser processes scribe the light emitting polymer (LEP) layer in OLED manufacturing. Picosecond processing ablates the material before it has time to react thermally resulting in consistent scribes than minimize the surface debris field and eliminate cleaning steps.
Transparent conducting oxides (TCOs) are widely used in the photovoltaics (PV) and electronic displays requiring ultrafast laser processing to pattern or structure these thin TCO films. Our laser processes utilize the high peak power of our visible and IR ultrafast lasers can lead to significantly cleaner scribe channels <20um width) that create excellent electrical isolation (>20MΩ).
Ultrafast laser processing for medical device manufacturing industry included materials such as nitinol, cobalt chrome, heat-sensitive polymers, and borosilicate glass. Machining of biological inert polymers enable implantable devices and drug delivery. Part or device marking below a surface coating so not to compromise the biological barrier. The pulsewidths of picosecond laser process allows for the machining of low energy materials like FEP and PEEK without generating the 'melt' stage during ablation. This results in sharp, clean edges unlike the melted edges of nanosecond processing.
Many solar cell products are based on silicon wafer and the laser processing of backside passivation. Ultrafast drilling processes form holes through the passivation layer without damaging the underlying crystalline silicon to maintain the cell performance and excellent electrical contact.
Transparent Materials - glass, polymers, plastics, oxides
Picosecond laser processes enable nonlinear absorption with multi-photon absorption that focuses picosecond pulses onto the surface of transparent materials to etch patterns for applications like etched markings, optics, microfluidics, and wafer scribing. With IR or green wavelengths being transparent to the materials like glass substrates, laser processing through glass allows for backside processing from the topside.
Ultrafast fiber laser marking can produce security watermarks that are only visible under specified lighting conditions. These marks can be on the surface on internal the transparent material. When the surface layer is transparent to a particular wavelength, the underlying layer can be marked without compromising the surface layer.