Metallurgical AuSn Bonding of Piezoelectric Layers
Bibliographic record
Abstract
This study presents a novel and simple approach to form metallurgical bonds between layers of the acoustic stack in an ultrasound transducer using a eutectic AuSn preform, which is a pre-shaped thin sheet of solder. The bonding takes 10 minutes and yields uniform bondlines of 10 μm with a melting temperature of 280 °C. The resulting bonds are electrically conductive, mechanically robust and have a characteristic acoustic impedance of 29 Mrayls. AuSn bonding was demonstrated by successfully bonding two equally thick layers of PZT. The bonded PZT-stacks were polarized and sub-diced into a 2-dimensional array. Characterization was performed by optical microscopy, scanning acoustic microscopy and electrical impedance measurements. Combining scanning acoustic microscopy and electrical impedance measurements proved to be a useful approach to experimentally study inter-element variations induced by varying concentrations of voids in a metallurgical bondline.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".