Is the coating thickness uniform or are there variations in the application?
The only limitation imposed on the size of a component / device that can be coated is the dimensions and volume of the vacuum chamber, in which the coating is produced. The chamber’s common shape and dimensions are a barrel/cylindrical shape, ½ meter in diameter at most, and with a height of 60cm. Simtal has been developing new capabilities that extend the dimensions even further (~150%), depending on specific project requirements.
In effect, there is no limit to the thickness Parylene coatings can reach. However, when considering possible coating thickness, one must remember that Parylene is different from other conformal coats, as a thinner coat of Parylene will perform far better than its competition.
Simtal is capable of maintaining almost flawless thickness conformity between cycles.
Parylene coating is transparent. Shades ranging from full transparency to a complete opaque white can be reached, while conforming to the requirements of the device or apparatus.
The quantity per cycle /application is proportional to the dimension of the coated device/apparatus, its geometry and other requirements.
Parylene can provide excellent physical characteristics even when a coating of single microns is applied. The necessary thickness will be determined by the requirements of the specific application.
Determining how long a coating process might take varies and is based on professional considerations and customer needs. In general, the rate of settling is ¼ micron per hour, to 3-4 microns per hour in rare cases.
It all depends on the volume of the coated device/apparatus; maximizing the number of devices in a single batch will decrease the cost per unit. Parylene can therefore be more cost effective compared to other coating methods. Moreover, it is important to remember that Parylene’s unique characteristics are unmatched by other conventional coatings.
Parylene provides a multi-disciplinary solution, which meets specific standards and does not contradict other device standards, but rather improves on the general performance of the device. For example, the ability to seal off fluids, does not conflict with the ability to transmit RF signals; in fact the device will even show greater resistance to a phenomena known as ‘Tin Whiskers’ for years to come. With other conventional coatings, combining these solutions and characteristics would not be possible.
The Parylene coat is sensitive to mechanical cutting stress; while being extremely durable to impact. The coating is sensitive to prolonged UV exposure, under a specific spectrum when coupled with the presence of oxygen. The absence of Oxygen eliminates UV sensitivity.
Under suitable conditions and in the right environment, the coating is expected to last decades..
What is the removal procedure?The coating is resistant to all types of chemicals, even the most aggressive ones. Therefore, the only way to remove the coating is by employing mechanical or thermal methods (heat).