Dry Film Photo-Imageable Dielectric Enabling Glass Core Substrate TGV Filling and Build-Up

Glass core substrate technology has attracted much attention recently because of the superior electrical, thermal and mechanical properties of glass as compared to a conventional organic core. A key technical challenge in fabricating glass core substrate is through glass via (TGV) filling. DuPont CYCLOTENE ${ }^{\text {TM }}$ DF-PID (dry film photo-imageable dielectric) has been developed for panel level application and has excellent cavity filling capability that are uniquely suited for glass core substrate build-up and TGV filling. In this paper, a glass core substrate test vehicle (TV) was built-up with CYCLOTENE ${ }^{\text {TM }}$ DF-PID. It has dual side RDL structure, with total of six layers of RDL and six layers of DF-PID. In this TV demonstration, DF-PID shows void-free filling to $100 \mu ~\mathrm{m}$ diameter TGVs across $400 \mu ~\mathrm{m}$ thick glass via vacuum lamination. A daisy chain and comb structure were fabricated with a dry semi-additive process with a minimum L/S of $9 / 12 \mu ~\mathrm{m}$. Through $10 \mathrm{x} 260^{\circ} \mathrm{C}$ reflow, no delamination between DF-PID/Cu/glass was observed. In addition, TV passed e-test for bHAST and a high temperature stress test. This provides strong evidence that DuPont CYCLOTENE ${ }^{\text {TM }}$ DFPID can enable high-reliability glass core substrate build-up with dielectric-filled TGV approach.