Maskless manufacturing of through glass vias (TGVS) and their test structures

Through glass vias (TGVs) are a key component in glass-based interposers and microelectromechanical-system lid wafers. Magnetic-field-assisted self-assembly has been demonstrated earlier in fabrication of through silicon vias. Here we present an entirely maskless TGV fabrication process utilizing magnetic assembly. Femtosecond laser is used for ablative direct patterning of surface metal layers and for exposing the TGV conductors after wafer thinning. The proposed TGV structure is shown to be electrically functional by measuring the TGV resistance values.