Magnetic field simulation of magnetic alignment technology for wafer bonding

Abstract

Integrated circuit chip manufacturing is the core area of the national strategy, and wafer bonding is a key process for 3D advanced packaging. In order to solve the error problems caused by optical alignment, large stroke motion and position calibration. Based on the magnetic tunnel junction effect, a new wafer magnetic alignment technology is proposed in this paper, which is expected to reduce the difficulty in the design and manufacture of wafer bonding equipment. The wafer magnetic alignment scheme and mechanism are introduced. The magnetic field distribution of wafer magnetic field alignment is numerically simulated and visualized. The relationship between alignment accuracy and the shape, magnetic field distribution and remanence of micro column markers is studied. The analysis shows that the magnetic alignment technology can achieve the wafer alignment accuracy to 1μm. On this basis, a wafer bonding machine scheme is proposed. This research has certain significance for promoting the development of key technologies of advanced IC packaging equipment.