1070-4272/03/7606-1014 $25.00 C 2003 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 76, No. 6, 2003, pp. 1014!1016. Translated from Zhurnal Prikladnoi Khimii, Vol. 76, No. 6, 2003,
Original Russian Text Copyright + 2003 by N. Polezhaeva, I. Polezhaeva, Levdanskii, Kuznetsov.
Preparation of Solder Powders and Properties
of Low-Temperature Solder Creams Based on a Polyester
Resin and Dimethylethylphenylammonium Iodide
N. I. Polezhaeva, I. V. Polezhaeva, V. A. Levdanskii, and B. N. Kuznetsov
Institute of Chemistry and Chemical Technology, Siberian Division, Russian Academy of Sciences,
Received January 10, 2003
Abstract-Solder powders were prepared, and properties of solder creams based on rosin-modified polyester
resin and dimethylethylphenylammonium iodide were studied. The possibility of using dimethylethylphenyl-
ammonium iodide as a flux in low-temperature solder creams was examined.
Solder creams consist of a powdered solder and
an organic binder containing a flux . Particles of
the solder powder should have definite size and shape
and should not be oxidized. The best results are ob-
tained with particles 3325 mm in size .
The functioning of a solder cream depends on the
size of solder powder particles: The smaller the parti-
cles, the higher the probability of their oxidation.
Oxidation can occur in the course of cream fabrica-
tion, after fabrication (before use), and during applica-
tion. Oxidation of the solder powder is undesirable,
since additional power is required to remove the oxide
Procedures for pulverizing solids are numerous .
The simplest procedure is mechanical grinding in
special installations (mills or crushers). However, this
procedure is unsuitable for grinding solders because of
their high plasticity. Ultrasonic spraying of a molten
solder is performed as follows. A molten solder is
slowly poured onto the vibrating end of the concentra-
tor of an ultrasonic atomizer and is sprayed in the
form of drops, which are deposited after cooling as a
powder in a special collector. The drawback of this
procedure is that it requires sophisticated equipment;
furthermore, it is difficult to prevent the powder oxi-
dation in the course of the process. Spraying of a
molten solder in a special sprayer with compressed
gas also requires sophisticated equipment to obtain a
This work continues our studies aimed at develop-
ment of formulations of low-temperature corrosion-
inactive solder creams with different melting points,
using quaternary ammonium salts as fluxes [43 6].
The solder powder was prepared as follows. The
solder was placed in a glass reaction vessel, and
VM-1S industrial oil was added. The mixture was
heated to a temperature exceeding by 30350oC the
melting point of the solder, after which the electric
stirrer was switched on. The mixture was cooled with
stirring to a temperature below the melting point of
the solder. Then the stirrer was switched off, and the
powder was separated after sedimentation by decant-
ing and washed with benzine and acetone.
From the obtained powders of various composi-
tions, we prepared low-temperature solder creams
based on the following solders: POSK 50-18, mp
1603180oC; solder of the composition 45% Sn, 29%
Pb, 17% Cd, and 9% In, mp 1603180oC; and POIN-
52, mp 120oC .
To determine the optimal particle size of the solder,
we separated the powder by sieving into fractions with
particle size of 1310, 10350, and 503100 mm.
From these powder fractions, we prepared solder
formulations applied onto contact areas of test printed-
circuit boards. The contact areas were prepared by
thick-film technology from Ag-containing and Ag3Pd
conductor formulations, and also from thin-film cop-
per conductors with a protective tin or gold coating.
No significant catalytic effect of metals entering into