Aerosol Jet Printed 3D Interconnects Enable Millimeter Wave Applications over 100GHz

As mmWave applications increase in the global communications, automotive and mil/Aero markets and expand above traditional mmWave frequency bands, the onus of limiting the signal parasitics associated with interconnects has never been more important. Techniques such as copper bumps and 3DIC packaging introduce complications and costs to designers that wire bonds do not. However, as the frequency climbs, transmission line widths diminish and the limitations of traditional wire or wedge bonding techniques become a real problem for package designers. Printed 3D Interconnects made with Aerosol Jet printing provide package designers and RF engineers a new tool to tailor the impedance of transition interconnects for active die, tailoring the loss characteristics to the application need and eliminating the need to compensate for poor signal through loss and back reflection behavior. Printed 3D interconnects are digitally designed into the package and can be made of noble metals like gold, with the ability to create high conductivity traces. As they are conformal to the surface of the package, the trace length can be minimized, creating lower inductance pathways to transition from transmission line to active die circuitry specifically for die on board, die in trench, or die on die with pads up packaging configurations. We will share examples showcasing similar loss performance to transmission lines with no breaks, significantly improving the performance when compared to bond wires and ribbons.