Laser-PSFL Versatility
Laser-PSFL: Versatility
​Direct patterning of thin film coatings​​​​​​​​​​​
​The illustration below shows the basic single mask mode of using Laser-PSFL technology for the direct patterning of, for example, a vacuum vapour deposition coating (additive process).
​The gold deposition is a whole area process meaning that residual gold is deposited on the whole surface of the mask as well as in the pattern apertures laser cut in it. Because of the nature of the low force mechanical peel-off of the whole area sheet film mask removal, it is possible for the residue material to be efficiently collected for subsequent reclamation using a suitable process.
​Although the illustration shows a typical metal coating, in this case gold, other materials types including semiconductor, insulator, piezoelectric, magnetic, etc. could be patterned using this method.
​An alternative to opaque metal conductors for many applications is transparent conductive oxides (TCO's). A few applications where low temperature physical vapour deposited (PVD) TCO materials such as ITO, AZO, and GZO, are used include:​​
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Transparent circuits [Interconnections]
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Photonic devices [Electrical contacts]
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Automobile and building glazing [Optical antennas and invisible circuitry]
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Sensor and transducers [Micro heaters]
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Displays [Touch and slider switches]
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Electronic windows [Liquid crystal layer light valve switching]
Device fabrication
The illustration below shows patterned dashed and continuous conductive tracks for an XY addressable array of open access contacts for device evaluation. The picture shows the transferred electrical isolation film covering the junction between the dashed and continuous orthogonal tracks prior to the patterning of the conductive bridge link along each dashed tracks that enables the XY addressing on a single side of a substrate ( 2 or 3 mask process).
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Selective area temporary protection of a surface
The illustration (top layer of dual layer mask shown partially transparent for clarity purposes) below shows how Laser-PSFL masks can be used for comparative assessment of sensing devices by locating a reference device in a sealed cavity along size an equivalent device under liquid exposure testing. ​​​​​​
Other examples of potential use, such as for materials property and device operation testing and measurements include:
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Deuterated and Oxygen18 water exposure for analysis of oxide composition and barrier coating uptake
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Electric field stressing of barrier coatings
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Electric field stressing of immersed electrical contacts and passivation
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Electro-wetting on dielectric (EWOD) devices
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Gas exposure of thin film coatings for oxidation resistance testing
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Selective area ion implantation masking
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Liquid exposure of medical devices
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Liquid containment and channelling assessment for microfluidic devices
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Controlled surface exposure for assessing material or coating corrosion
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Permanent structures
The illustration below shows how Laser-PSFL masks can be used for applications requiring a permanent structure such as in the partially embedded conductive track shown. In this case the Laser-PSFL mask is a 2-level structure comprising a permanent-attach base layer and a peelable capping layer. For the application illustrated a thick conductive track was required to be partially embedded in an insulating layer. The process used for the conductive track patterning was a squeegee draw down method with the track pattern being defined when the capping layer was mechanically peeled off taking the residual conductive material deposit with it. The Laser-PSFL approach is a simpler and more versatile alternative to screen printing, especially for R&D use where pattern revisions to track pattern layout can be achieved quickly. ​​​​​
Other potential uses of this mode of applying Laser-PSFL technology include microfluidic channels, containment wells, and substrate-superstrate stand-off spacers.​​​​​