학술논문

Fabrication of High-Density Micro-Bump Arrays for 3D Integration of MEMS and CMOS
Document Type
Conference
Source
2023 22nd International Conference on Solid-State Sensors, Actuators and Microsystems (Transducers) Solid-State Sensors, Actuators and Microsystems (Transducers), 2023 22nd International Conference on. :1488-1491 Jun, 2023
Subject
Bioengineering
Components, Circuits, Devices and Systems
Fields, Waves and Electromagnetics
Photonics and Electrooptics
Robotics and Control Systems
Micromechanical devices
Wet etching
Suspensions (mechanical systems)
Transducers
Three-dimensional displays
Dry etching
Silicon
3D integration
Cu-Sn bonding
MEMS
CMOS
Language
ISSN
2167-0021
Abstract
Cu-Sn transient-liquid-phase bonding has a limit in achieving small diameter/high-density bumps due to the extrusion of the melted Sn layer during bonding. This paper report a new method that can fabricate small diameter Cu-Sn bumps with 5μm diameter and 25μm pitch based on a new thermal reflow and pre-bonding method that enables solid-state Cu-Sn reaction for avoiding Sn extrusion. Using the new method, 3D integration of a 640 × 480 MEMS array on a CMOS circuit chip has been demonstrated. This method can be used in 3D integration of MEMS arrays and CMOS circuits such as micromirror arrays.