Direct Printing of 1-D and 2-D Electronically Conductive Structures by Molten Lead-Free Solder
Abstract
:1. Introduction
2. Experimental Methods
2.1. Apparatus and Method Description
2.2. Materials and Sample Preparation
2.3. Inkjet Printing Conditions
3. Results and Discussion
3.1. Effects of Dot Spacing on Droplet Formation and Deposition
3.2. Effects of Motion Velocity on Droplet Formation and Deposition
3.3. Study of the Deposition Process by Changing the Substrate Temperature
3.4. Formation of 2D Electronically Conductive Structures
4. Conclusions
- The metallic line with a width of 55 μm can be successfully printed with respect to the value of the dot spacing (50 μm) and the stage velocity (50 mm∙s−1) at the substrate temperature of 30 °C. However, the L-shaped ridges of the lines on the solidified drop surface were formed for the time interval of 1 ms.
- With regard to the increase in sample temperature (from 30 to 70 °C), the height (from 0.63 to 0.58) and solidification contact angle (from 72° to 56°) of the metallic micro droplets gradually decreased on the substrate.
- The results of the SEM observations showed that the quality of 3D micro patterns improved significantly at 70 °C. The parallel lines of droplets were formed together with no visible micro pores on the interface between droplets.
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Parameters | Value | Unit | Symbol |
---|---|---|---|
Density | 7500 | kg∙m−3 | ρ |
Viscosity | 2 | mPa∙s | η |
Surface tension coefficient | 0.431 | N∙m−1 | σ |
Liquidus temperature | 221 | °C | θl |
Solidus temperature | 216 | °C | θs |
Specific heat of liquid | 250 | J∙kg−1∙°C−1 | Cp |
Equilibrium freezing temperature of solder | 217 | °C | Tm |
Latent heat of fusion | 64,762 | J∙kg−1 | L |
Condition | Pulse Time (μs) | Drop Frequency (Hz) | Pulse Voltage (V) | Jet Height (mm) | Reservoir Pressure (kPa) | Sample Temperature (°C) | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Trise | Tdwell | Tfall | Techo | Tfinalrise | VDC | V1 | V2 | |||||
A | 200 | 20 | 2 | 6 | 6 | 200 | −40 | −35 | −50 | 0.5 | 1.0 | 30 |
B | 200 | 20 | 2 | 6 | 6 | 100 | −40 | −35 | −50 | 0.5 | 1.0 | 30 |
C | 200 | 20 | 2 | 6 | 6 | 50 | −40 | −35 | −50 | 0.5 | 1.0 | 30 |
D | 200 | 20 | 2 | 6 | 6 | 1000 | −40 | −35 | −50 | 0.5 | 1.0 | 30 |
E | 200 | 20 | 2 | 6 | 6 | 1000 | −40 | −35 | −50 | 0.5 | 1.0 | 50 |
F | 200 | 20 | 2 | 6 | 6 | 1000 | −40 | −35 | −50 | 0.5 | 1.0 | 70 |
Sample Temperature (°C) | Weber Number | Reynolds Number | Ohnesorge Number | Stefan Number | The Average Width of Metallic Line (μm) |
---|---|---|---|---|---|
30 | 0.92 | 206.25 | 4.7 × 10−3 | 0.722 | 55 ± 1.3 |
50 | 0.92 | 206.25 | 4.7 × 10−3 | 0.645 | 56 ± 1.4 |
70 | 0.92 | 206.25 | 4.7 × 10−3 | 0.567 | 59 ± 1.7 |
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Wang, C.-H.; Tsai, H.-L.; Hwang, W.-S. Direct Printing of 1-D and 2-D Electronically Conductive Structures by Molten Lead-Free Solder. Materials 2017, 10, 1. https://doi.org/10.3390/ma10010001
Wang C-H, Tsai H-L, Hwang W-S. Direct Printing of 1-D and 2-D Electronically Conductive Structures by Molten Lead-Free Solder. Materials. 2017; 10(1):1. https://doi.org/10.3390/ma10010001
Chicago/Turabian StyleWang, Chien-Hsun, Ho-Lin Tsai, and Weng-Sing Hwang. 2017. "Direct Printing of 1-D and 2-D Electronically Conductive Structures by Molten Lead-Free Solder" Materials 10, no. 1: 1. https://doi.org/10.3390/ma10010001
APA StyleWang, C.-H., Tsai, H.-L., & Hwang, W.-S. (2017). Direct Printing of 1-D and 2-D Electronically Conductive Structures by Molten Lead-Free Solder. Materials, 10(1), 1. https://doi.org/10.3390/ma10010001