Effects of ultrasonic capillary dynamics and pad material on the mechanics of thermosonic ball bonding
Bibliographic record
Abstract
A frequency response model of thermosonic ball bonding is reported studying the effects of the ball/pad materials on the mechanical stresses of ultrasound under the bonding pad. The model includes chip, wire, and capillary tool, is matched to experimental results, and calculates the underpad stress fields. Assuming perfect elasticity, the stress values increase when replacing Au wire with Cu wire and decrease when using Ni as a pad material. For the standard Au-Al process, the maximum principal stress magnitude (MPS) under the pad is 490 MPa and compressive. With the harder Cu wire instead of the Au wire, less ultrasound amplitude is required while MPS increases with the same bond quality (interfacial shear) maintained. When Ni is used to replace the softer Al pad material, MPS is reduced. A Cu wire combined with a Ni pad results less than 2% higher MPS than with the Au-Al combination.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".