Selectively Sealing Porosity and Cracks in Anodized Aluminum for Dielectric Protection
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
Disclosed is a method for selectively sealing cracks in anodized alumi- num circuit cards by using an organic material which polymerizes when exposed to ultraviolet light. Thick anodic coatings on aluminum panels have good potential for electronic card applications by offering high voltage breakdown and excellent thermal dissipation. However, the nature of the anodic growth on the base aluminum yields cracks in the anodic layer at sharp transitions, such as via holes and card edges. These cracks extend to the aluminum core of the anodized panel such that circuitry over such cracks can easily short to the core.