Abstract
In this paper, a novel wafer-level hermetic packaging technology for heterogeneous device integration is presented. Hermetic sealing is achieved by low-temperature thermo-compression bonding using electroplated Au micro-sealing frame planarized by single-point diamond fly-cutting. The proposed technology has significant advantages compared to other established processes in terms of integration of micro-structured wafer, vacuum encapsulation and electrical interconnection, which can be achieved at the same time. Furthermore, the technology is also achievable for a bonding frame width as narrow as 30 μm, giving it an advantage from a geometry perspective, and bonding temperatures as low as 300 °C, making it advantageous for temperature-sensitive devices. Outgassing in vacuum sealed cavities is studied and a cavity pressure below 500 Pa is achieved by introducing annealing steps prior to bonding. The pressure of the sealed cavity is measured by zero-balance method utilizing diaphragm-structured bonding test devices. The leak rate into the packages is determined by long-term sealed cavity pressure measurement for 1500 h to be less than Pa m3s-1. In addition, the bonding shear strength is also evaluated to be higher than 100 MPa.
Original language | English |
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Article number | 015029 |
Journal | Journal of Micromechanics and Microengineering |
Volume | 27 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2017 Jan |
Keywords
- Au-Au thermo-compression bonding
- hetero-integration
- single-point diamond fly-cutting
- wafer-level hermetic sealing
- zero-balance method
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering