Encapsulant solutions are commonly used to enhance protection of circuit boards from environmental and liquid contaminants, chemical attack, and electrical shortages. While potting materials provide many positive attributes when used to protect PCBs, sometimes other issues arise during and post application of these compounds. This blog focuses on “bubbles” forming within the encapsulant itself.
When conventional coating methods such as hand spray, total dipping or robotic selective coating don’t provide the protection required, there is always selective dip coating.
What is selective dip conformal coating?
Selective dip coating is a process whereby the substrate rather than globally immerised in the coating, is discreetly coated in desired locales. The technique in one form or another, has been around for over 25 years and is used with both classic solvent-based coatings and 100% UV cure conformal coatings.
Have you ever seen your conformal coating separate or de-wet? Have you observed the conformal coating to flake off after cure? The key to your success is understanding the relationship between surface energy (of the substrate) and surface tension (of the conformal coating). There are some simple steps you can take to help ensure you possess a healthy balance of both.
This blog post outlines the techniques required for the removal of HumiSeal UV cure conformal coating. The products covered in this article are:
- UV40, UV40-250
- UV500, UV500LV
There are 3 methods for the removal of HumiSeal UV conformal coatings:
- Mechanical removal: Powder Micro Abrasion
- Thermal removal: Burn Through
- Chemical removal
All three methods will effectively remove the coating, depending on the process requirements, to allow individual component replacement and subsequent re-coating.