In this study, fully cured low-temperature polyimide (PI) films and 〈111〉, 〈110〉, 〈200〉, and 〈211〉-oriented Cu films on Si wafers were chosen to investigate the grinding effect on Cu/PI pattern wafers. PI is chemically inert and low cost with good mechanical properties, which is a promising material for hybrid bonding. However, it is challenging to remove PI during chemical mechanical planarization (CMP) process. The removal rate of PI is dominated by the abrasive grinding mechanism. By adjusting the mechanical parameters (abrasive type, size, dose, and platen velocity), we explored the desorption/adsorption (Kpad) and repulsion (Krep) coefficients using a modified Langmuir adsorption model. Such a tool enables us to predict and discover the optimal PI grinding interval. Additionally, results showed that the hardness of Cu with different orientations varied and was inversely proportional to the removal rate. It was found that the 〈111〉-oriented nanotwinned Cu (NT-Cu) possessed high surface hardness and low polishing rate, which benefited the CMP process of Cu/PI hybrid joints. The optimal height profile of NT-Cu/PI was adjusted by abrasives and pad types. PI recess was achieved while Cu was protected from further dishing under harsh grinding environment. As characterized by atomic force microscopy, Cu protrusion of 200 nm was obtained, achieving excellent bonding interfaces for the NT-Cu/PI hybrid bonding under a thermal compression bonding (TCB) process at 220 ℃ for 1 h with 8.3 MPa.