Unlocking the True Power of Additive Manufacturing for EMI Shielding

Abstract

Miniaturization trends in electronic packaging led to reduced spacing of individual packages on the printed circuit boards and thus increased the overall electromagnetic interference (EMI) levels within a device. State-of-the-art conformal coatings as EMI shielding layers are typically applied via sputter technology and offer design limitations with respect to coating selectivity on individual positions of the overall package. Our new technology of additively Ag layer application via inkjet printing overcomes today’s design limitations and is key enabler for next generations packaging designs. In this study, we compare the shielding effectiveness (S.E.) on specifically designed transmission line emitter samples coated with state-of-the-art sputtered conformal layers against silver coatings applied via inkjet printing of particle free metal organic decomposition inks to evaluate the new technology for its potential on package level shielding performance. Mechanical and electrical characterization of the silver coatings indicate appropriate tools to specify layer characteristics and ensure S.E. of 40 dB or higher at frequencies of 800 MHz and higher. The suitability of our well-tailored silver coatings to match typical S.E. requirements is shown with even much thinner layer thickness as compared to state-of-the-art coatings.