By Ralph Delmdahl, Rainer Pätzel, Rolf Senczuk and Jan Brune

Glass is a promising material from which advanced interposers for high density electrical interconnects for 2.5D and 3D chip packaging can be produced. The supply of ultra-thin glass wafers with thicknesses of 100 µm and below shows attractive cost and superior high frequency performance relative to polished thin wafers made of silicon. As thin glass is extremely brittle, micromachining to create through glass vias is particularly challenging and laser processing using deep UV excimer lasers at a wavelength of 193 nm and ultra-short pulse laser provide a viable solution. Continue reading →