**Table 2.**

 *Magnesium-containing Sn-based active solders and melting ranges.*



**Table 3.**

**55**

**4. Active soldering**

**Figure 4.**

**Table 4.**

high-temperature activation [43].

Active soldering is a flux-free soldering process. The active solders can be activated by exposure to high temperature or mechanical agitation [41, 42]. Joining with low melting point active solders such as Sn10Ag4Ti and Pb4In4Ti is always conducted at elevated temperatures above 700°C, owing to the decent thermodynamic activation. Chai et al. [22] investigated the wettability of Sn10Ag4Ti on SiC and Al2O3 substrates. They indicated that the contact angles decreased with increases in temperature and heating time. The contact angle of the Sn10Ag4Ti filler metal on SiC decreased almost to 0° when the temperature was raised above 680°C. Ti aggregated strongly in the Sn10Ag4Ti/SiC and Sn10Ag4Ti/Al2O3 interfaces after brazing at 700°C. Koleňák et al. [43] indicated that the wettability of Sn3.5Ag4Ti(Ce, Ga) solder depended on temperature and wetting time. Wettability of the Sn3.5Ag4Ti(Ce, Ga) solder on Al2O3 was achieved with heating at 850°C for 43 min [42]. The schematic in **Figure 5** illustrates the wetting process of low melting point filler metal with

*Microstructure of the bonding interface of Al2O3/Al2O3 joint with Sn3.5Ag0.5Cu1Mg filler metal.*

**Solder Sn Zn Bi In Ag Cu Mg** M–SZB Bal. 5–15 0.1–10 0 0 0 0.1–5 M–SZI Bal. 5–15 0 0.1–10 0 0 0.1–5 M–SZA Bal. 5–15 0 0 0.1–10 0 0.1–5 M–SZBI Bal. 5–15 0.1–10 0.1–10 0 0 0.1–5 M–SZBA Bal. 5–15 0.1–10 0 0.1–10 0 0.1–5 M–SZBC Bal. 5–15 0.1–10 0 0 0.1–5 0.1–5 M–SZIA Bal. 5–15 0 0.1–10 0.1–10 0 0.1–5 M–SZIC Bal. 5–15 0 0.1–10 0 0.1–5 0.1–5

This soldering process, normally implemented under low temperature, requires mechanical activation to destruct the oxide layer forming on the liquid molten filler, after which the active elements Ti and rare earth elements can allow metallurgical

*Active Solders and Active Soldering*

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

*Magnesium-containing SnZn-based active solders.*

*Magnesium-containing In-based active solders and melting ranges.*

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


### **Table 4.**

*Fillers - Synthesis, Characterization and Industrial Application*

**54**

M–I M–IA M–IAC

M–IC M–IS M–ISB

M–IZ

**Table 3.**

*Magnesium-containing In-based active solders and melting ranges.*

0

Bal.

0

0

1–15

0

0

0.1–5

145–156

10–30

Bal.

0

0

0

0

10–40

0.1–5

60–100

30–60

Bal.

0

0

0

0

0

0.1–5

120–150

0

Bal.

0

0.1–2

0

0

0

0.1–5

150–160

0

Bal.

0.5–5

0.1–2

0

0

0

0.1–5

145–160

0

Bal.

0.5–5

0

0

0

0

0.1–5

144–160

0

Bal.

0

0

0

0

0

0.1–5

150–160

*Magnesium-containing SnZn-based active solders.*

### **Figure 4.**

*Microstructure of the bonding interface of Al2O3/Al2O3 joint with Sn3.5Ag0.5Cu1Mg filler metal.*
