Printable Materials and Devices
Printing technologies provide a simple solution to build electronic circuits on low cost flexible substrates. Materials will play an important role for developing advanced printable technology. Advanced printing is a relatively new technology and needs more
characterization and optimization for practical applications. In the present paper,we examine the use of different materials in the area of
printing technology. A variety of printable nanomaterials for electronic packaging have been developed. This includes nano
capacitors and resistors used as embedded passives,nano laser materials,optical materials,etc. Materials can provide high
capacitance densities,ranging from 5 nF/inch2 to 25 nF/inch2,depending on composition,particle size and film thickness. The
electrical properties of capacitors fabricated from BaTiO3-epoxy nanocomposites showed a stable dielectric constant and low loss over a frequency range from 1MHz to 1000MHz. Reliability of the nanocomposites was ascertained by IR-reflow,thermal cycling,pressure cooker test (PCT),and solder shock. Change in capacitance after 3X IR-reflow and after 1000 cycles of deep thermal cycling (DTC) between -55oC and 125oC was within 5%. A variety of printable discrete resistors with different sheet resistances,ranging from ohm to Mohm,processed on large panels (19.5 inches x 24 inches) have been fabricated. Low resistivity materials,with volume resistivity in the range of 10-4 ohm-cm to 10-6 ohm-cm depending on composition,particle size,and particle loading can be used as conductive joints for high frequency and high density interconnect applications. The CITC (Current Induced Thermal Cycling) life at 245C is greater than 10 cycles and life at 220C is over 25 cycles to fail, which is at least equivalent to copper PTH (plated through hole) performance. Thermosetting polymers modified with ceramics or
organics can produce low k and low loss dielectrics.