Effect of shear rate on lead free solder joint strength
Bibliographic record
Abstract
Solder joint strength at high strain rates is a critical reliability requirement for portable electronic devices. Experimental observations showed low shear rate tests of solder joints cannot be used to accurately predict the mode of deformation and failure behaviors under high speed impact condition. Due to strain rate effect, brittle failure of solder joints under dynamic loadings may not take place at low strain rates. Thus, characterization of solder joints under impact becomes critical in package design and manufacturing for high reliability. This is particularly true for lead-free solder in handholds devices. Present study focused on the deformation and failure behavior of single solder ball joints under impact conditions. With a newly designed single-ball impact tester, impact strength of ball joints of two lead-free solders, i.e. Sn-1Ag-0.5Cu (SAC105) and Sn-1.2Ag-0.5Cu-Ni (LF35), were tested at a speed varying from 0.5 to 3m/s. Peak load and fracture energy obtained at different speeds were compared. The failure modes of the joints were studied by scanning electron microscope (SEM) and correlated to the peak load and total fracture energy which were strain rate dependent and changed with solder ball composition due to different strain hardening effects of the two lead-free solders.
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 | 0.000 |
| 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".