Formance K has been developed to deposit pure, solderable silver layer on copper circuitry in compliance with IPC specification no. IPC-4553A. The deposit satisfies Class 3 final finish durability and is an excellent choice for demanding Pb-free assembly. Formance K is an easy to use product with simple analytical controls and straightforward replenishment that leads to lower running cost. Notably, the chemistry is EDTA- and alkylphenol ethoxylate-free and thus biodegradable.
Formance K is used in a standard immersion line, vertical or horizontal, incorporating the chemical steps of Cleaner, Microetch, Predip and Silver Bath with counterflow rinses in between. It is recommended to use an acidic cleaner appropriate for a final finish line (such as FinClean from RBP). The use of persulfate-based microetch is strongly recommended as it creates a better surface topography for immersion silver plating. An example of such microetch is Circutek ME-515 from RBP. Formance K Predip and Silver Bath are prepared from the components described below.
An acid, organic, non-etching cleaner that has been specifically formulated to remove organic and inorganic contaminants. NC ACID CLEANER removes soils such as fingerprints, oxides and chromate conversion coating prior to photoresist lamination, oxide treatment, and multilayer lamination to improve adhesion. It is compatible with photoresists making it effective for pattern plate cleaning. Its non-chelating formula cleans and conditions copper surfaces and can be followed by a microetch for optimum performance. It is effective in both spray and soak applications.
An acid soak cleaner that removes oxidation, tarnish and organic soils from copper surfaces. POSICLEAN M is formulated to clean effectively in a variety of applications such as pre-clean prior to copper pattern plate, prior to dry film lamination, prior to oxide process, and as a pre-clean for tin or tin/lead electroplating. POSICLEAN M can be followed by a microetch when necessary for increased adhesion.