Printable Nanocomposites for Advanced Organic Packaging

This paper examines the use of nanocomposites or materials in the area of printing technology. A variety of printable nanomaterials for advanced organic packaging have been developed. This includes nano capacitors and resistors as embedded passives, nano magnetic materials, multifunctional materials, etc. Nanocomposites 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 capacitance and low loss over a temperature range from 25degC to 100degC. A variety of printable discrete resistors with different sheet resistances, ranging from 1 ohm to 120 Mohm, processed on large panels (19.5 inches times 24 inches) have been fabricated. Low resistivity nanocomposites, with volume resistivity in the range of 10^-4 ohm-cm to 10^-6 ohm-cm depending on composition, particle size, and loading can be used as conductive joints for high frequency and high density interconnect applications. Thermosetting polymers modified with ceramics can produce low k dielectrics with k value in the range between 5.41 and 3.59. Similarly, low loss dielectric materials can be produced form mixing epoxy with silica or other low loss fillers. 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 -55degC and 125degC was within 5%. Most of the nanocomposites in the test vehicle were stable after IR-reflow, PCT, and solder shock.