Investigation of Sn–3.0Ag–0.5Cu Bump Arrays Prepared by the Pulsated Orifice Ejection Method

By targeting advances in electronic packaging technologies, an innovative strategy has been applied for fabricating bump arrays. Herein, a 3D motion platform is equipped with pulsated orifice ejection method for direct bump deposition. This method enables on-demand bump printing within the orifice diameter range, achieving a deposition accuracy of 6 μm at a bump pitch of 62 μm. The stable jetting process and precise deposition significantly enhance the accuracy and repeatability of bump fabrication. Notably, an increase in substrate temperature improves the shear force of the bump. The 200 μm Sn–3.0Ag–0.5Cu bump achieves a shear force of 2238.7 mN and forms a scalloped Cu₆Sn₅ intermetallic compound, thereby improving the reliability of the bump. This method demonstrates significant potential for applications in flip-chip bumping and direct printing of microelectronic components.