Lead and cadmium
free : these
according to EU standards 2000/53/EG
(automobile), 2002/95/EG (RoHS), 2002/96/EG (WEEE), 2003/11/EG
Tarnish preventive EN-20: If it is tempered without a protective gas above 300
°C for obtaining a higher degree of hardness, electroless nickel
layers tarnish. The application of Tarnish preventive EN prevents
discolourations up to 450 °C! Protective gases are no longer
necessary. Result: Reduction of tempering times by higher
temperatures and the surface remains as deposited.
Wetting agent EN-2 and
Wetting agent EN-20: The application of
wetting agents in electroless nickel baths is necessary in order
to avoid pores but also to counter bad smells by means of a
blanket of foam. In addition, a decrease of the surface tension is
effected in the electroless nickel electrolyte whereby the
light-off performance and the first deposition (germination) are improved.
Nickel acetate bath : Due to the usual hydrogen ion
development the acetate changes to acetic acid which escapes with
an increasing working temperature from the electroless nickel
bath. The MAK value of 25 mg/m3 air is exceeded.
Problems to health might be caused for the operating personal.
Zinc and aluminium in electroless nickel : The influence of
zinc and aluminium in electroless nickel is known due to zincate
treated aluminium surfaces. Two possibilities produce a relief:
Either an application of a stabile electroless pre nickel bath
(approx. 55 °C) or novel, surface selective components, which
bind zinc and aluminium and to remove it from the electroless
Accelerator for electroless nickel : Is effective in
contaminated as well as in electroless nickel bath with a lot of
By applying the accelerator the deposition speed increases from 2
to 5 µm/h follows.
pH correction without ammonia and
carbonate : Hydroxide,
actually 130 g/L NaOH, is the alternative to ammonia and carbonate. Under
the condition that the electroless nickel system works with this pH
correction, I can recommend adequate processes for fast depositing as well
as for high-phos baths without cutbacks for the individual functionality !
The passable and known problems with ammonia and
also with carbonate applications belong to the past.
without ammonia is now also possible for electroless prenickel baths and/or for
plastic coatings at approx. 40 °C +/- 5 ! In this case with 500
g/L KOH or 500 g/L K2CO3.
: If aluminum being
treated with zincate is supposed to be nickel plated, it is not sufficient
to have a very agreeable pretreatment, the pH-value is also very decisive
in the electroless nickel bath. With the pH ranging between 5.0 and 5.2, a
better coverage is achieved. This helps to avoid
blisters as well as difficulties in general during the deposition process.
: Examinations showed
that specific Al-alloys can be plated with electroless nickel
Therefore it is possible to restrain from zincate treatments. Blisters or various pretreatment difficulties
don`t have to be accepted anymore ! On the
contrary, only a few pretreatment steps presumably synchronized suffice
for a perfect electroless nickel plating.