EBASOLDER UT-55
The EBASOLDER UT-55 process is the fluorine-free semi-bright tin plating bath and deposits a fine film with a uniform semi-bright appearance in a wide range of current density. consistent semigloss appearance in a wide range of current density. The film comprises crystal grains of appropriate size and little change in the stress in electrodeposits over time after plating assures good whisker suppression effect. Because of that feature, the process is applicable to the plating of IC lead frames.
Features
1.
Deposits a uniform, semi-bright film with excellent solderability.
2.
Little change in stress in electrodeposits over time after plating assures good whisker suppression effect.
3.
No deterioration in solderability after heat treatment.
4.
Has excellent covering and throwing power.
5.
Allows high-speed plating at high current density.
Excellent whisker suppression effect
Solderability equal to that of Sn-Pb
Why is it hard to form whisker?
Small change in the stress in electrodeposits over time
Proper precipitate particle size and low internal stress
Particle size (surface SEM picture)
Internal stress (X-ray diffraction/Θ-2Θ method)
UT-55
-1±3MPa
Traditional bath
-23±4MPa
Small quantity of co-deposition of organic substances
Plating bath
Co-deposition quantity of carbon
Co-deposition quantity of sulfur
Co-deposition quantity of nitrogen
UT-55（Sn）
0.0026
0.0006
0.0006
Traditional bath（Sn）
0.0081
0.0019
0.0018
HS-805（Sn/Pb）
0.0029
0.0009
0.0010
C, S: Infrared absorptiometric method after combustion
N: Inert gas carrier melting thermo-conductometric method
Chemicals for electronic parts
