‘Spalling’ of SAC Pb free solders when used with nickel substrates
Bibliographic record
Abstract
The term “spalling” refers to the formation in a solder joint of a second layer of intermetallic compound, in addition to and separate from the usual single layer that normally forms on the substrate. It has been observed in Pb-free solders of the SAC type when used in conjunction with a nickel finish. Explanations offered to account for this phenomenon have been based on thermodynamic phase equilibria observed in isothermal sections of the Sn corner of the Cu–Ni–Sn system at temperatures 20°C or more above the solidification temperature of the solder, and without regard to reactions that occur at low temperatures, during freezing. Recent measurement of the liquidus projection of the Sn corner of the Cu–Ni–Sn system as shown the occurrence of a ternary quasiperitectic reaction in the composition range in which “spalling” is observed. Evaluation of the effect of this quasiperitectic reaction shows that its operation during freezing of the solder can account for the “spalling” phenomenon.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| 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 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".