A comparative study of the thermomechanical reliability of fully-filled and conformal through-glass via
Ke Pan, Chukwudi Okoro, Yangyang Lai, Dhananjay Joshi, Seungbae Park, Scott Pollard
Abstract
This study investigates the thermomechanical response of the copper TGV during thermal cycling. Two different geometries of copper TGV, the fully-filled TGV and conformal TGV, are compared concerning their in-plane and out-of-plane deformation. The TGV samples were heated from room temperature (RT) 23 °C to 400 °C and then cooled to RT. The protrusion height of the copper TGV was recorded as a function of temperature, and unrecoverable copper protrusions were observed because of the creep of the copper at high temperatures. Two-dimensional digital image correlation (2D DIC) measurements were employed to obtain the in-plane deformation of the glass substrate near the copper TGV. It was found the copper protrusion height and the in-plane deformation of the glass substrate were significantly reduced in the conformal TGVs compared to the fully-filled TGVs.