Facilities
Description:
- V2 and V3 Sub-Micro Mechanical Tester: Due to the complex microstructures of solder alloys and their strong strain-rate dependence, most commercial mechanical testers do not adequately provide (i) sub-micrometer displacement-control precision to avoid load-train compliance problems and (ii) zero-backlash cyclic loading capability. To address these limitations, all experiments in CoSMAP Lab were conducted using the custom-made micro-precision closed-loop mechanical tester. The platform employs closed-loop position control to achieve sub-micrometer precision in specimen displacement, which is critical for joint-scale solder characterization. A capacitance displacement sensor provides real-time feedback for displacement control, mitigating the influence of load-train compliance and enabling stable strain-rate control during monotonic and cyclic loading. Potential loading-axis misalignment is monitored through off-axis force measurements using a six-axis load cell, followed by micro-scale adjustments to minimize parasitic loading.
- Nano Mechanical Tester: The primary motivation for developing the nano-precision mechanical tester was to improve displacement-control performance for smaller specimen geometries, where the required accuracy increases as solder joint dimensions shrink. The nano-precision mechanical tester also provides (i) sub-micrometer displacement-control precision and (ii) zero-backlash capability for cyclic loading. With its higher resolution, the nano-precision mechanical tester enables testing of microbump specimens with standoff heights as small as 10 µm.
Specifications:
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Feature |
V3 Mirco Mechanical Tester |
V2 Mirco Mechanical Tester |
Nano Mechanical Tester |
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Joint-scale testing |
Captures pad/joint micro-structure effects |
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Closed-loop control |
Necessary for joint-scale testing |
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Reversed loading |
Zero backlash, cyclic loading capable |
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Capacitance sensor |
500 µm range; 10 nm resolution |
250 µm range; 7 nm resolution |
40 µm range; 0.15 nm resolution |
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6-axis load cell |
Z (shear direction): ±400 N (0.05 N res)X / Y: ±130 N (0.025 N res) |
Z (shear direction): ±200 N (0.025 N res)X / Y: ±65N (0.013 N res) |
Z (shear direction): 100N to -20N (0.02 N res) |
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Thermal chamber |
-70°C to 250 °C |
30°C to 120 °C |
NA |
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Software |
Customizable through LabVIEW® |
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Experimental Setup of the V3: Sub-Micro Mechanical Tester
Experimental Setup of the V2: Sub-Micro Mechanical Tester
Experimental Setup of the V1: Nano Mechanical Tester
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