Papers by Keyword: Materials Removal Ratio

Abstract: Slurry preparation is of paramount importance in chemical mechanical planarization (CMP) process. It couples the combination effects of chemical and mechanical ones. In this paper, the characteristics of the slurry particles used in CMP are firstly modeled, which includes the size and the concentration with primary priority. And then, the model is validated by experiments during hard disk wafer polishing. The slurry prepared contributes to a high quality hard disk surface processed with CMP, which leads to low waviness Wa and roughness Ra with suitable material removal rate (MRR) as well. The study will surely lay a feasible foundation to the CMP mechanism.

Abstract: Dry Electrical discharge machining (Dry EDM), using gas as dielectric, has been developed to solve problems against environment. It has both advantages of high material removal ratio (MRR) and low relative electrode wear ratio (REWR). We investigated the effect of duty factor, peak current, and reference ratio of gap voltage on MRR and REWR of Dry EDM, respectively. Moreover, trying to prove the attachment on electrode surface could decline REWR. It is considered that melting material of work-piece was sputtered and stuck onto electrode surface, and to become a protection layer as result in low REWR. However, the attachment will be removed under the condition of high peak current and high discharge frequency. But the amount of attachment just has little change when discharge number and arc discharge ratio are both decrease.

Abstract: Dual-lapping was a process to planarize the surface of the sapphire wafer, the nature of surface&subsurface damage and the surface uniformity was depended on the material removal mode and materials removal ratio. Material removal mode was studied in this paper, and the model of material removal was set up too. The SEM was used to scan the processed sapphire surface and the different removal style (two body and three body) were discovered. This research provided valuable insights into the material removal ratio and the dependence of lapping-induced damage on dual-lapping conditions, the asymmetry of abrasive granularity brought on the different materials removal mode and the surface asymmetry. The model was set up to qualitative analysis the material removal ratio in dual-lapping of sapphire, obtain the reasonable MMR and optimize the surface quality and the planarization result.