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.
A copper oxide process uniquely formulated to produce a variety of oxide coatings ranging from a very fine-grained bronzed oxide to a larger grained black oxide. MAGNABOND CO-300 provides the flexibility to manipulate the grain size allowing for processing a wide variety of dielectric materials while maintaining optimum inner-layer bonding.
VersaPrep is formulated to microetch multiple metallic surfaces and thus improve their processing including lamination, imaging and solder mask application. Microetching results in surfaces that are cleaner, with removed or reduced oxide and with higher roughness. These mechanisms occur to a different extent on different metals. VersaPrep is effective on aluminum, stainless steel, copper, copper alloys and selected other alloys such as Inconel. Different substrates can be treated with simple adjustments of concentration, temperature and contact time. VersaPrep can be used in either spray or soak mode.
HASL Precleaner SLTM is a powerful, non-foaming, free rinsing, alkaline cleaner specifically designed to clean copper prior to HASL or alternative finishes. It will remove solder mask developer scum, oven baked oxidation and residues, fingerprints, and oils. HASL Precleaner SLTM will not etch copper nor will it damage the. HASL Precleaner SLTM can be used in conjunction with a light microetch or acid cleaner. If an acid cleaner is used, MicroCleanTM ZE is preferred. If a microetch is used, much lower levels of metal removal are fully acceptable, thus minimizing costs and reject rate. Because of the potent cleaning agents that destroy organo-metallic compounds (such as insoluble copper/soldermask compounds) present on the copper surfaces, use of HASL Precleaner SLTM will reduce the requirement for a second pass through the HASL.