Issue link: https://iconnect007.uberflip.com/i/442619
January 2015 • The PCB Magazine 15 CAN THE ELECTRONICS INDuSTRy uSE 3D PRINTING? continues Note that the deposition size is typically smaller than the hole in the donor layer. Fur- ther, the substrate and the donor both move with respect to the laser beam, each with their own velocity. This is needed in order to create overlapping deposits which form a conducting line. Inkjet printing can be used in electronics packaging as interconnections between elec- tronic components. Conductive inks and dielec- tric inks are used when substituting traditional PCBs with inkjet-printed interconnections. Al- though both organic and inorganic inks can be used for conductive purposes, at the moment inorganic inks offer better conductivity. Inor- ganic ink consists of metal nano-particles and organic solvent which make the ink printable. Aerosol jet printing is another material de- position technology for printed electronics. The process begins with atomization of an ink, which can be heated up to 80°C, producing droplets on the order of one to two microns in diameter. The atomized droplets are entrained in a gas stream and delivered to the print head. Here, an annular flow of clean gas is introduced around the aerosol stream to focus the drop- lets into a tightly collimated beam of material. The combined gas streams exit the print head through a converging nozzle that compresses the aerosol stream to a diameter as small as 10 microns. The jet of droplets exits the print head at high velocity (~50 meters/second) and imping- es upon the substrate. Electrical interconnects, passive and active components are formed by moving the print head, equipped with a me- chanical stop/start shutter, relative to the sub- strate. The resulting patterns can have features ranging from 10 microns wide, with layer thick- nesses from 10s of nanometers to >10 microns. A wide nozzle print head enables efficient pat- terning of millimeter size electronic features Figure 3: graphic explanation of liFT process. Figure 4: 3D miD examples (far right shows a functional 3D miD). FEaturE