**5. Conclusion**

With the rapid development of new materials and advanced technology in various industries, joining technologies play increasingly important roles. The poor wettability of ceramics for conventional filler metals and the large thermal residual stress make it extremely difficult to obtain sound ceramic/metal joints. Adding active elements such as titanium, rare earth elements, and magnesium to conventional solders provides improved wettability and bonding strength of most metals, glasses, and ceramics. The newly developed low melting point active solders and flux-free active soldering technology can effectively reduce the thermal stress between the ceramic and metal. Moreover, the active soldering process can be performed without the need for premetallization of difficult-to-wet materials and without flux or a protective atmosphere. In a number of cases, fluxless soldering is a necessary condition of optoelectrical devices, glass-to-metal, and ceramic-to-metal sealing. Additionally, active soldering can offer an economic metallization process for high-power ceramic substrates such as direct bonded copper (DBC), direct bonded aluminum (DBA), and active metal bonded (AMB). It has been shown that the active soldering has a great potential to improve the joining properties of difficult-to-wet materials. A gas-tight joint of ceramic/metal can be realized at low temperature (<250°C) in air without the need of premetallization for ceramic. Moreover, the active soldering process can also be applied to metallize the ceramics for electric and heat conduction and electroplating. Thus, this process provides lowcost, high-quality, environmental benefits and convenient joining technology.

**59**

**Author details**

Shih-Ying Chang1

provided the original work is properly cited.

and Technology, Touliu, Yunlin, Taiwan

\*, Yan-Hua Huang1

Science and Technology, Neipu, Pingtung, Taiwan

\*Address all correspondence to: changsy@yuntech.edu.tw

*Active Solders and Active Soldering*

*DOI: http://dx.doi.org/10.5772/intechopen.82382*

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

1 Department of Mechanical Engineering, National Yunlin University of Science

2 Graduate Institute of Materials Engineering, National Pingtung University of

and Lung-Chuan Tsao2

*Active Solders and Active Soldering DOI: http://dx.doi.org/10.5772/intechopen.82382*

*Fillers - Synthesis, Characterization and Industrial Application*

In10Ag4Ti solder at 230°C.

**5. Conclusion**

**Figure 9.**

reported by Hillen et al. [4] presented an ultrasonic vibration method using an ultrasonic soldering iron, as shown in **Figure 9**. Ultrasonic vibration can effectively improve the wettability of active solder. Yu et al. [48] have reported that applying ultrasonic vibration during the soldering process causes the active solders Sn–Ag–Ti and Sn–Ag–Ti–Al to spread on the graphite surface at 450°C in air. Koleňák et al. [49] successfully used ultrasonic-assisted soldering to join SiC and copper with

With the rapid development of new materials and advanced technology in various industries, joining technologies play increasingly important roles. The poor wettability of ceramics for conventional filler metals and the large thermal residual stress make it extremely difficult to obtain sound ceramic/metal joints. Adding active elements such as titanium, rare earth elements, and magnesium to conventional solders provides improved wettability and bonding strength of most metals, glasses, and ceramics. The newly developed low melting point active solders and flux-free active soldering technology can effectively reduce the thermal stress between the ceramic and metal. Moreover, the active soldering process can be performed without the need for premetallization of difficult-to-wet materials and without flux or a protective atmosphere. In a number of cases, fluxless soldering is a necessary condition of optoelectrical devices, glass-to-metal, and ceramic-to-metal sealing. Additionally, active soldering can offer an economic metallization process for high-power ceramic substrates such as direct bonded copper (DBC), direct bonded aluminum (DBA), and active metal bonded (AMB). It has been shown that the active soldering has a great potential to improve the joining properties of difficult-to-wet materials. A gas-tight joint of ceramic/metal can be realized at low temperature (<250°C) in air without the need of premetallization for ceramic. Moreover, the active soldering process can also be applied to metallize the ceramics for electric and heat conduction and electroplating. Thus, this process provides lowcost, high-quality, environmental benefits and convenient joining technology.

*Schematic of ultrasonic vibration soldering with an ultrasonic soldering iron [4].*

**58**
