Simple and practical methods for utilizing parylene C film based on vertical deposition and laser patterning

We propose two novel methods to effectively utilize parylene C films. First, we demonstrate a vertical deposition method capable of depositing a parylene C film of the same thickness on both sides of a sample. Through this method, we have formed parylene C films with a thickness of 4 μm on both sides of the sample with a thickness deviation of less than 2.5%. Further optical verification indicates that parylene C films formed by this method have a very uniform thickness distribution on each side of the surfaces. Second, we propose a debris-tolerant laser patterning method as a mask-less means to fabricate self-supporting ultrathin parylene C films. This method does not involve any photolithography and entails a simple and rapid process that can be performed using only a few materials with excellent biocompatibility. It is demonstrated that patterned parylene C films exhibit a high degree of surface uniformity and have various geometrical shapes so that they can be used for substrates of highly flexible and/or stretchable devices. Finally, we use both of the proposed methods to fabricate flexible, stretchable, and waterproof-packaged bifacial blue LED modules to illustrate their potential in emerging applications that would benefit from such versatile form factors.