Symposium Conference Proceedings


Innovative Nanocoatings for High Volume Conformal Coating of Electronics

Authors: Eva Rogge, MSc and Filip Legein, MSc, MBA
Company: Europlasma NV
Date Published: 4/14/2015   Conference: Symposium


Abstract: Plasma is considered to be the fourth state of matter. By adding energy matter can be transformed from solid into liquid into gas into plasma. In plasma the molecules are decomposed into a mixture of neutral and charged particles that will interact with all exposed surfaces of the material. In case the object has an open cell structure, the plasma particles will interact with the inner surface as well. In low pressure plasma technology a stable and effective plasma is created by an electromagnetic discharge of a gas at low pressure and at low temperature.

In recent years low pressure plasma technology has been improved to deposit nanocoatings with specific functionalities on materials. Materials can be made permanently hydrophilic, super-hydrophobic and/or superoleophobic by using the right chemistry and equipment. An increasing number of these nanocoating systems are being used in mass production of electronic devices, electronic subassemblies or their individual electronic components. Recent improvements in process and machine design allow to deposit high end superhydrophobic and/or super-oleophobic nanocoatings in a repeatable and uniform fashion.

RoHS- and WEEE-compliant super-hydrophobic and/or super-oleophobic low pressure plasma conformal nanocoatings protect electronic devices and their components, e.g. printed circuit boards (PCBs), against humidity and corrosive environments. The flexibility and nano-thickness of the coatings allows to coat complicated 3D-structures with excellent coverage and uniformity without any impact on acoustic performance. Although the coatings are insulators in the x- and y-plane of the substrate, they are z-axis conductive. Consequently, they obviate the use of masking and allow for flexible integration in the assembly and manufacturing process. To waterproof electronic devices, the nanocoating needs to work well with the mechanical design as well: reduction of water ingress, nanocoating the internal electronics, and easy draining of ingressed water from the device.

The main limitation of the current low pressure plasma nanocoatings is that they inhibit, but not completely prevent corrosion, particularly on a powered device. Typical solutions are µm-thick coatings which are not zaxis conductive and need extensive masking, losing the flexibility in the manufacturing process. Europlasma is now working on a new generation of nanocoatings which give nearly complete protection against corrosion without the need for masking, maintaining full flexibility for integration in the manufacturing process.

One of the key drivers of low pressure plasma is the reduced environmental impact compared to traditional wet chemical processes. Zero water consumption means a “dry” technology. The processes are performed on a molecular scale, hence the consumption of chemicals is reduced to an absolute minimum. Plasma treatment is thus a “clean” technology as well. A last advantage is the reduced energy consumption, because no post-treatment such as heating, drying or curing is needed.

This leads to nanocoatings that can be used in many applications. The system design and size is adaptable to the dimensions of the products to be coated. In most cases there exists a suited low pressure plasma treatment with well-dimensioned equipment to help improve protection of electronics.

Key Words: 

Low pressure plasma nanocoating, conformal coating, corrosion resistance, splash-proof



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