Aspect is an organic solderability preservative developed for high temperature processing in Pb-free assembly. It is compatible with through-hole and surface count technology. It can be used for mixed final finish, ENIG/OSP applications. Aspect is supplied in three concentrated components, two for bath make-up and an additional component for non-regular replenishment. It contains a substituted imidazole, acetic acid and is Cu-free. Treated Cu surfaces are covered with a thin (0.2 – 0.4 micron), nearly colorless and transparent coating.
Aspect is used in a standard immersion line incorporating the chemical steps of Cleaner, Microetch, and OSP with counterflow rinses in between. Rinsing and drying between each step will prevent variations in coating thickness. It is recommended to use an acidic cleaner appropriate for a final finish, such as FinClean CR or FinClean RS from RBP, as well as a peroxide-based microetch as this chemistry creates a better surface topography for coating formation. Peroxide microetch chemistry is also more easily rinsed. An example of such microetch is Quantum Etch from RBP. Aspect bath make-up instructions are provided in the Product Data Sheet.