Figure 1.
Formation of soldered joint: (a) joint used for solder/substrate interface analysis, (b) joint used for shear strength test.
Figure 1.
Formation of soldered joint: (a) joint used for solder/substrate interface analysis, (b) joint used for shear strength test.
Figure 2.
Schematic representation of the soldering process in the presence of ultrasonic energy.
Figure 2.
Schematic representation of the soldering process in the presence of ultrasonic energy.
Figure 3.
Shear strength measurement scheme.
Figure 3.
Shear strength measurement scheme.
Figure 4.
TG/DTA solder analysis of Zn3Mg1.5Sr heating at 5 °C/min, second heating.
Figure 4.
TG/DTA solder analysis of Zn3Mg1.5Sr heating at 5 °C/min, second heating.
Figure 5.
TG/DTA solder analysis of Zn3Mg1.5Sr cooling at 5 °C/min, second cooling.
Figure 5.
TG/DTA solder analysis of Zn3Mg1.5Sr cooling at 5 °C/min, second cooling.
Figure 6.
Equilibrium binary diagram of magnesium-zinc system (Re-printed with permission from ASM International) [
26].
Figure 6.
Equilibrium binary diagram of magnesium-zinc system (Re-printed with permission from ASM International) [
26].
Figure 7.
Microstructure of Zn3Mg1.5Sr solder from SEM (BEI) analysis in as-etched condition.
Figure 7.
Microstructure of Zn3Mg1.5Sr solder from SEM (BEI) analysis in as-etched condition.
Figure 8.
Point energy dispersive X-ray analysis of Zn3Mg1.5Sr solder.
Figure 8.
Point energy dispersive X-ray analysis of Zn3Mg1.5Sr solder.
Figure 9.
Equilibrium binary diagram of strontium–zinc system (Re-printed with permission from ASM International) [
26].
Figure 9.
Equilibrium binary diagram of strontium–zinc system (Re-printed with permission from ASM International) [
26].
Figure 10.
XRD analysis of solder Zn3Mg1.5Sr.
Figure 10.
XRD analysis of solder Zn3Mg1.5Sr.
Figure 11.
Map of (a) microstructure solder, (b) Zn, (c) Mg, and (d) Sr elements in the microstructure of Zn3Mg1.5Sr solder.
Figure 11.
Map of (a) microstructure solder, (b) Zn, (c) Mg, and (d) Sr elements in the microstructure of Zn3Mg1.5Sr solder.
Figure 12.
Microstructure of boundary in SiC/Zn3Mg1.5Sr/Cu-SiC joint from the SEM analysis performed in BSE regime.
Figure 12.
Microstructure of boundary in SiC/Zn3Mg1.5Sr/Cu-SiC joint from the SEM analysis performed in BSE regime.
Figure 13.
Map of (a) microstructure solder, (b) Mg, (c) Zn, and (d) Sr elements in the microstructure of solder after soldering of SiC/Zn3Mg1.5Sr/Cu-SiC joint.
Figure 13.
Map of (a) microstructure solder, (b) Mg, (c) Zn, and (d) Sr elements in the microstructure of solder after soldering of SiC/Zn3Mg1.5Sr/Cu-SiC joint.
Figure 14.
Microstructure of transition zone in SiC/Zn3Mg1.5Sr joint.
Figure 14.
Microstructure of transition zone in SiC/Zn3Mg1.5Sr joint.
Figure 15.
Point energy dispersive X-ray analysis of SiC/Zn3Mg1.5Sr joint.
Figure 15.
Point energy dispersive X-ray analysis of SiC/Zn3Mg1.5Sr joint.
Figure 16.
Equilibrium binary diagram of silicon–zinc system (Re-printed with permission from ASM International) [
26].
Figure 16.
Equilibrium binary diagram of silicon–zinc system (Re-printed with permission from ASM International) [
26].
Figure 17.
Planar distribution of (a) joint microstructure, (b) O, (c) Mg, (d) Si, (e) Zn, and (f) Sr elements on the boundary of SiC/Zn3Mg1.5Sr joint.
Figure 17.
Planar distribution of (a) joint microstructure, (b) O, (c) Mg, (d) Si, (e) Zn, and (f) Sr elements on the boundary of SiC/Zn3Mg1.5Sr joint.
Figure 18.
Line EDX analysis of Si/Zn3Mg1.5Sr joint. Transition zone with a marked line (a); (b) oxygen; (c) magnesium; (d) silicon; (e) zinc; (f) strontium; concentration profiles of elements.
Figure 18.
Line EDX analysis of Si/Zn3Mg1.5Sr joint. Transition zone with a marked line (a); (b) oxygen; (c) magnesium; (d) silicon; (e) zinc; (f) strontium; concentration profiles of elements.
Figure 19.
Mechanism of the joint formation.
Figure 19.
Mechanism of the joint formation.
Figure 20.
Point energy dispersive X-ray analysis of Cu-SiC/Zn3Mg1.5Sr joint.
Figure 20.
Point energy dispersive X-ray analysis of Cu-SiC/Zn3Mg1.5Sr joint.
Figure 21.
Isopletic cross-section through the Cu-Mg-Zn ternary system for 5 wt. % Mg (Re-printed with permission from Elsevier) [
27].
Figure 21.
Isopletic cross-section through the Cu-Mg-Zn ternary system for 5 wt. % Mg (Re-printed with permission from Elsevier) [
27].
Figure 22.
Isopletic cross-section through the Cu-Mg-Zn ternary system for 15 wt. % Mg (Re-printed with permission from Elsevier) [
27].
Figure 22.
Isopletic cross-section through the Cu-Mg-Zn ternary system for 15 wt. % Mg (Re-printed with permission from Elsevier) [
27].
Figure 23.
Line EDX analysis of Cu-SiC/Zn3Mg1.5Sr joint: (a) the transition zone with a marked line, (b) concentration profiles of Zn, Cu, Si, and Mg elements.
Figure 23.
Line EDX analysis of Cu-SiC/Zn3Mg1.5Sr joint: (a) the transition zone with a marked line, (b) concentration profiles of Zn, Cu, Si, and Mg elements.
Figure 24.
The map of (a) joint microstructure, (b) Cu, (c) Zn, (d) Mg, (e) Si, (f) O, and (g) Sr elements on the boundary of Cu-SiC/Zn3Mg1.5Sr joint.
Figure 24.
The map of (a) joint microstructure, (b) Cu, (c) Zn, (d) Mg, (e) Si, (f) O, and (g) Sr elements on the boundary of Cu-SiC/Zn3Mg1.5Sr joint.
Figure 25.
Shear strength of soldered joints fabricated by use of Zn3Mg1.5Sr solder.
Figure 25.
Shear strength of soldered joints fabricated by use of Zn3Mg1.5Sr solder.
Figure 26.
(a) Fractured surface of SiC/Zn3Mg1.5Sr/Cu-SiC joint; (b) Fractured surface of SiC/Zn3Mg1.5Sr/Cu-SiC joint with higher magnification.
Figure 26.
(a) Fractured surface of SiC/Zn3Mg1.5Sr/Cu-SiC joint; (b) Fractured surface of SiC/Zn3Mg1.5Sr/Cu-SiC joint with higher magnification.
Figure 27.
Fractured surface of SiC/Zn3Mg1.5Sr/Cu-SiC joint and the planar distribution of individual elements: (a) fracture structure, (b) Mg, (c) Si, (d) Cu, (e) Zn, (f) Sr.
Figure 27.
Fractured surface of SiC/Zn3Mg1.5Sr/Cu-SiC joint and the planar distribution of individual elements: (a) fracture structure, (b) Mg, (c) Si, (d) Cu, (e) Zn, (f) Sr.
Figure 28.
XRD analysis of fractured surface from SiC/Zn3Mg1.5Sr joint boundary.
Figure 28.
XRD analysis of fractured surface from SiC/Zn3Mg1.5Sr joint boundary.
Table 1.
Composition of Zn-Mg-Sr solder and ICP-AES chemical analysis results [wt. %].
Table 1.
Composition of Zn-Mg-Sr solder and ICP-AES chemical analysis results [wt. %].
Specimen | Charge [wt. %] | ICP-AES [wt. %] |
---|
Zn | Mg | Sr | Zn | Mg | Sr |
---|
Zn3Mg1.5Sr | 95.5 | 3 | 1.5 | 96.04 | 2.84 | 1.12 |
Table 2.
Soldering parameters.
Table 2.
Soldering parameters.
Ultrasound power | 400 | [W] |
Working frequency | 40 | [kHz] |
Amplitude | 2 | [μm] |
Soldering temperature | 150 | [°C] |
Time of ultrasound activation | 5 | [s] |
Table 3.
Important temperatures of phase transformations achieved by TG/DTA analysis.
Table 3.
Important temperatures of phase transformations achieved by TG/DTA analysis.
DTA Analysis | TL (°C) | TE (°C) |
---|
Heating | 1st | 368 | 365 |
2nd | 368 | 364 |
Cooling | 1st | 370 | 356 |
2nd | 370 | 357 |
Table 4.
Results from energy dispersive X-ray analysis on Zn3Mg1.5Sr solder.
Table 4.
Results from energy dispersive X-ray analysis on Zn3Mg1.5Sr solder.
Spectrum | Mg [at.%] | Zn [at.%] | Sr [at.%] | Solder Component |
---|
Spectrum 1 | 8.41 | 91.59 | - | Eutectic (Zn) + Mg2Zn11 |
Spectrum 2 | 9.13 | 90.87 | - | Eutectic (Zn) + Mg2Zn11 |
Spectrum 3 | - | 92.81 | 7.19 | SrZn13 phase |
Spectrum 4 | - | 92.81 | 7.19 | SrZn13 phase |
Spectrum 5 | - | 100.00 | - | Zn matrix |
Spectrum 6 | - | 100.00 | - | Zn matrix |
Spectrum 7 | 34.05 | 65.95 | - | MgZn2 phase |
Spectrum 8 | 33.71 | 66.29 | - | MgZn2 phase |
Spectrum 9 | 16.61 | 83.39 | - | Mg2Zn11 phase |
Spectrum 10 | 16.19 | 83.81 | - | Mg2Zn11 phase |
Table 5.
The results from point energy dispersive X-ray analysis of SiC/Zn3Mg1.5Sr joint.
Table 5.
The results from point energy dispersive X-ray analysis of SiC/Zn3Mg1.5Sr joint.
Spectrum | Zn [at.%] | Mg [at.%] | Si [at.%] | O [at.%] |
---|
Spectrum 1 | 97.62 | 2.38 | 0 | 0 |
Spectrum 2 | 91.78 | 8.22 | 0 | 0 |
Spectrum 3 | 51.75 | 1.00 | 41.28 | 5.97 |
Spectrum 4 | 21.83 | 11.16 | 21.36 | 45.65 |
Spectrum 5 | 42.42 | 15.33 | 21.13 | 21.12 |
Table 6.
The results from point energy dispersive X-ray analysis of Cu-SiC/Zn3Mg1.5Sr joint.
Table 6.
The results from point energy dispersive X-ray analysis of Cu-SiC/Zn3Mg1.5Sr joint.
Spectrum | Zn [at.%] | Mg [at.%] | Si [at.%] | O [at.%] | Cu [at.%] |
---|
Spectrum 1 | 0 | 0 | 1.68 | 0 | 98.32 |
Spectrum 2 | 65.61 | 0 | 1.06 | 0 | 33.33 |
Spectrum 3 | 73.45 | 14.98 | 0 | 0 | 11.57 |
Spectrum 4 | 78.35 | 18.73 | 0 | 0 | 2.92 |
Spectrum 5 | 45.60 | 0.95 | 0 | 52.09 | 1.36 |