Abstract :
Providing the particle size, shape and size
distribution are suitable, appropriate dispersion media
and surface-active additives can usually be found for
the electrophoretic deposition (EPD) of powder with
any chemical composition. The design of the EPD cell
is largely dictated by the geometry of the final product
and the required dimensional tolerances. The integrity
of the microstructure and freedom of the product from
process defects commonly depend on the deposition
parameters and the dispersion chemistry.
Demonstrations of laboratory feasibility for EPD
products may prove straightforward, but developing an
EPD process technology that is suitable for mass
production can be far more challenging. This contribution
reports four examples:
1. The deposition of silver thermal sinks in lowtemperature,
co-fired ceramic (LTCC) tape vias.
2. The formation and printing of silver-base alloy lines
for conducting interconnects.
3. The embedding of passive ceramic components in
punched ceramic tape.
4. The production of porous conducting anodes for
solid electrolyte capacitors.
In each case, the process parameters have been
selected to satisfy the engineering requirements while
minimizing the formation of process defects. Observed
defects include variations in the particle packing
density; loss of adhesion to the substrate, cracking
of the deposit and surface roughness or thickness
variations.
