Bibliographic record
Abstract
Purpose Conductive anodic filament (CAF) is a failure mode in printed wiring boards (PWBS), which occurs under high humility and high voltage gradient conditions. This paper aims to review the history of CAF from its identification in the 1970s to the statistical analysis of its failure mode and the factors that enhance its formation. Design/methodology/approach Charts the chronology and details the developments of CAF over the last 30 years. Findings CAF is a conductive copper‐containing salt created electrochemically that grows from the anode toward the cathode sub‐surface along the epoxy/glass interface. It can also grow from the anode on one layer to a cathode on another. CAF was first discovered in 1976 and was identified as a catastrophic failure mode. It is enhanced by high humidity during storage or use, by high voltage gradient between anode and cathode, by certain soldering flux ingredients, by hole drilling, multiple thermal cycles during processing, and by higher processing temperatures associated with lead‐free solders. CAF is a copper hydroxy chloride salt and is a semiconducting material. Originality/value Our analytical tools today are far superior to those of these early researchers. Early data were obtained from chart recorders and manual plotting. Today we have computers for automated data collection and analysis and the sensitivity of the scanning electron microscope has improved significantly. The researchers of the 1970s and early 1980s characterized the basic factors associated with CAF and in many ways we are just repeating what they have done.
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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.004 | 0.003 |
| Science and technology studies | 0.002 | 0.006 |
| Scholarly communication | 0.003 | 0.005 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 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".