This is a brief description of our ENIG process:

• Electroless Nickel / Immersion Gold (ENIG) is a superior finish to other immersion finishes and organic coatings for excellent coverage, uniformity and fine-pitch features. The process has excellent corrosion resistance and mechanical strength for good solderability and aluminum wire bonding.  This finish has a long self-life and can withstand multiple thermal cycles.
• Our ENIG meets the requirements of IPC 4552.  Typical thickness's are 118-230 uin nickel followed by 2-5 microinch of immersion gold.  Our electro-less nickel formulation minimizes soldermask attack that can occur with other high temperature ENIG baths.  We also can run panels that have masked areas using primary photo-imageable resist.  Our nickel can deposit up to 800 uin if needed.  The phosphorous level in the nickel is 6-8%.
• We test the ENIG deposit monthly for phosphorous levels and deposit uniformity.
• We caution that immersion gold can corrod the nickel deposit if the dwell time in the bath is excessive.  It is for that reason that we only deposit up to 5 uin of immersion gold.