On-chip near-field electromagnetic shielding effect of electroplated copper layers

Abstract

Near-field electromagnetic loss of electroplated copper layers has been characterized for applications to multichip microsystems with on-chip electromagnetic protection. Copper layers in the thickness range of 0.2 mumsimilar to200 mum have been electroplated on Pyrex glass substrates. A pair of microwave transceivers 3.5 mm x 3.5 mm in size has been fabricated using electroplated nickel microloop antennas. An electromagnetic radiation loss of 10 dBsimilar to40 dB has been measured from the copper layers in the thickness range of 0.2 mumsimilar to200 mum for the wave bandwidth of 100 MHz similar to 1 GHz. The 0.2-mum-thick copper layer provides a shield loss of 20 dB at frequencies higher than 300 MHz while showing a predominant decrease of shield loss to the 10 dB level at lower frequencies. No substantial increase of shield effectiveness has been observed for copper shield layers thicker than 2 mum.