Conformal Coatings are used regularly in an attempt to cover technology designs on printed circuit boards (PCBs). Normally, this is done by using a pigmented (coloured) conformal coating which obscures the components below the conformal coating material.
This does effectively hide the circuit board and components initially. However, the relative success of this method is dependent on several factors. These are:
- How difficult is the conformal coating material to be removed or stripped?
- How determined is the protagonist in removing the conformal coating?
- Does the action of pigmenting decrease the performance of the conformal coating?
In terms of practicality this method does hinder initial viewing of the components. If a highly chemically resistant coating such as a polyurethane or epoxy conformal coating is used then it will indeed be difficult to remove the conformal coating. However, ultimately, if care and time is taken then methods such as chemical stripping and mechanical abrasion will lead to the coating being removed in time. It really does come down to the determination of the person stripping the conformal coating.
Finally, pigmenting, or colouring a conformal coating can lower the electrical performance so care must be taken in selecting the material. The coating can become more hydroscopic or have reduced insulation properties and this may be more of a critical factor than the removal of the coating itself.This was a guest post by Dr. Lee Hitchens from Nexus3C.