1070-4272/02/7504-0675 $27.00 C 2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 4, 2002, pp. 675!676. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 4, 2002,
Original Russian Text Copyright + 2002 by Polezhaeva, Polezhaev, Levdanskii, Kuznetsov.
Synthesis and Properties of Low-Temperature Solder Creams
Based on Polyester Resin
and Diethyldibenzylammonium Bromide
N. I. Polezhaeva, I. V. Polezhaev, V. A. Levdanskii, and B. N. Kuznetsov
Institute of Chemistry and Chemical Technology, Siberian Division, Russian Academy
of Sciences, Krasnoyarsk, Russia
Received September 10, 2001
Abstract-Synthesis and properties of solder creams based on polyester resin modified with rosin and dieth-
yldibenzylammonium bromide were studied. The feasibility of using diethyldibenzylammonium bromide as
soldering flux in low-temperature solder creams was analyzed.
The modern trend in the development of electronics
is the increase in the number of components per unit
volume, which is achieved by wide use of microas-
semblies and functional microelectronic devices. Elec-
tronic devices are produced to a significant extent
by hybrid integrated methods. In this case, the passive
section of the hybrid microchips (HMCs) can be pro-
duced by both thick- and thin-film procedures. The
working hours of the manual hybrid-circuit packaging
comprised nearly 50% of the total working hours of
the HMC production, and a decrease in the manual
operation is a topical problem.
At present, the component leads are connected to
thick-film pads of the chips by various methods:
adhesion connection, welding, and soldering. Solder-
ing with low-temperature creams is the most widely
used and effective method .
The organic fraction of the solder cream contains
three main components: flux, binder, and solvent .
These components provide the required consistence
of the solder cream, low melting temperature, and
high adhesion to the surface being soldered.
The flux in the solder cream is analogous to the
common fluxes; it removes oxide films from the sur-
face of metals being soldered and solder, protects
the contact surfaces from oxidation during soldering,
and decreases the surface tension of molten solder at
the metal3solder flux interface. Thus, the flux must
meet the following requirements: necessary activity
in the given temperature range, low corrosion activity
and toxicity, stability upon prolonged storage, and
easy elimination after soldering.
This paper continues our study aimed at the de-
velopment of low-temperature noncorrosive solder
creams [3, 4].
We used diethyldibenzylammonium bromide
(DEDBAB) flux. The solder cream was prepared as
follows: DEDBAB (2 g) was added to the polyester
resin (15 g) modified with rosin synthesized as de-
scribed in . The components were thoroughly
The parameters of the thermal-oxidative decom-
position of the resulting mechanical mixture of poly-
ester resin, DEDBAB, and flux were studied by dy-
namic thermogravimetry . For more correct de-
termination of the temperature of the onset of sample
decomposition, we recorded TG, DTG, and DTA cur-
ves. The thermogravimetric curves were registered on
an MOM Q-1000 device (Hungary) in the program-
med-heating mode. The sample (0.03 g) was heated
in a platinum crucible in air at a heating rate of
10 deg min
. The scales of the balance, DTA galva-
nometer, and DTG galvanometer were 50 mg, 1/ 3
and 1/10, respectively.
The thermal stability of the polyester resin with
added DEDBAB was determined from the tempera-
ture of the onset of sample decomposition [T
is the temperature at which the exothermic effect
(related to oxidation) appears in the DTA curve, and
is the temperature at which the DTG curve
starts to deviate from the horizontal] . The results
are listed in the table.