High performance IPDs (Integrated passive devices) and TGV (Through glass via) interposer technology using the photosensitive glass

In this paper, a new TGV interposer technology is introduced in which the through via could be made by using a photolithography and chemical wet-etching. To make fine and accuracy via-holes, etching properties of the glass are studied in various UV-exposure times. It is possible to make TGVs from 60 μm to 20 μm with a 4:1 aspect ratio. Based on the TGV process, a high-aspect-ratio metal is made and high-Q spiral inductors can be realized by using the technology. The fabricated inductor has a very thick signal height more than 80 μm and its Q factor is more than 30 at 2 GHz. To demonstrate the process technology, a 0.9 GHz LPF, which is can be used for the RF front-end of the GSM band, is designed and fabricated using the inductor. The realized LPF has very low insertion loss of only 0.31 dB at the pass band, and this value is an improvement of more than 32% compared with the normal LPF.