ISSN 1070-4272, Russian Journal of Applied Chemistry, 2016, Vol. 89, No. 9, pp. 1414−1420. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © L.A. Brusnitsyna, T.A. Alekseeva, E.I. Stepanovskikh, A.O. Osipchuk,
2016, published in Zhurnal Prikladnoi Khimii, 2016, Vol. 89, No. 9,
The technological processes for fabrication of printed-
circuit boards widely use the activation of the surface
and through holes with combined activating solutions
based on palladium(II) and tin(II). The process of acti-
vation with palladium salts consists in that catalytically
active centers are formed on the surface, and these cen-
ters further initiate deposition of metallic copper from
electroless copper plating solutions. Because of the high
cost of activating solutions based on palladium(II), one
of the main tasks is to preserve its stability and working
longevity [1, 2].
Preceding studies have shown that, when the surface
of through holes in foil-clad insulators is activated with
solutions based on palladium(II) and tin(II), there occurs
the reaction in which copper oxide is reduced on the
surface of the copper foil. As a result, Pd
ions are present in the combined activating
solution [3, 4].
In view of this circumstance, it can be assumed that
the expenditure of palladium(II) and tin(II) will be due to
the occurrence of side reactions for this process.
The goal of our study was to ﬁ nd the main channels
by which palladium dichloride and tin dichloride are
consumed from a combined activating solution based on
Pd(II) and Sn(II) and quantitatively analyze the consump-
tion dynamics of the main components, which will make
it possible to determine the optimal composition and the
optimal working mode of this activating solution.
The following reagents were used to prepare the
combined activating solution: palladium dichloride,
tin dichloride dihydrate, hydrochloric acid, and sodium
chloride, all of pure grade.
A combined activating solution of the following
composition was taken as the starting solution (g L
O 1.0, SnCl
O 45.0, HCl (37%) 35.0,
and NaCl 120.
Solutions containing less than 1 g L
chloride were prepared by dilution of the starting con-
centrated solution as follows: the required amount of tin
dichloride was dissolved at a temperature of 70–80°C
was dissolved in a small part of hydrochloric acid, and
the solution was cooled and introduced into an aliquot
of the combined activating solution under vigorous
agitation. Further, the solution was boiled for 10 min,
cooled, and brought to the mark with a solution of so-
dium chloride in the remaining amount of hydrochloric
acid and in water.
Variation Dynamics of Palladium(II) and Tin(II)
Concentrations in Activating Solution
L. A. Brusnitsyna
*, T. A. Alekseeva
, E. I. Stepanovskikh
, and A. O. Osipchuk
Ural Federal University named after the ﬁ rst President of Russia B. N. Yeltsin,
ul. Mira 19, Yekaterinburg, 620002 Russia
Ural Institute of the State Fire Service of the Ministry of Emergency Situation of Russia,
ul. Mira 22, Yekaterinburg, 620062 Russia
Received July 14, 2016
Abstract—A study of the possibility of optimizing the efﬁ ciency of a catalytic palladium layer demonstrated
that the minimum palladium adsorption providing a sufﬁ cient catalytic activity of the surface is Γ
= 3.178 ×
, which can be reached at a palladium dichloride concentration of 0.035 g L
. It was shown that
palladium(II) activates the surface of the insulator (is sorbed) from a true, rather than a colloid solution.