  This paper reports on formation of high aspect micro patterns on low
temperature co-fired ceramic (LTCC) substrates by integrating micro inkjetting
with electroless plating. Micro inkjetting was realized by using an inkjetting
printer that ejects ink droplets from a printhead. This printhead consists of a
glass nozzle with a diameter of 50 micrometers and a piezoelectric transducer
that is coated on the nozzle. The silver colloidal solution was inkjetted on a
sintered CT800 ceramic substrate, followed by curing at 200 degrees C for 60
minutes. As a result, the silver trace with a thickness of 200 nm was obtained.
The substrate, with the ejected silver thin film as the seed layer, was then
immersed into a preinitiator solution to coat a layer of palladium for
enhancing the deposition of nickel. Electroless nickel plating was successfully
conducted at a rate of 0.39 micrometers /min, and the thickness of traces was
plated up to 84 micrometers. This study demonstrates that the integration of
inkjetting with plating is an effective method to form high aspect patterns at
the demand location.
