Nasa-Dod Pb-Free Electronics Rework Project: Effect Of 1x And 2x Eutectic Solder Rework On Vibration Reliability
Bibliographic record
Abstract
ABSTRACT Crane Naval Surface Warfare Center, a NASA-DOD Consortium member, added 30 test vehicles to the NASA-DOD Pb-free Electronics study (Project 2) in support of their Naval Supply Command (NAVSUP) sponsored “Logistics Impact of Pb-free Circuits/Components” project to quantify the effects of rework of Pb-free solder joints with SnPb solder. Multipass SnPb 1X and 2X rework was performed on Pb-free DIP, TQFP-144, TSOP-50, LCC and QFN components on SAC305 (24 boards) and SN100C (6 boards) soldered assemblies. Nine (9) boards were tested in drop shock, nine (9) in vibration, and eight (8) in accelerated thermal cycling test. The boards were vibration tested for one hour each at 8, 10, 12, 14, 16, 18, 20, and 28 Grms. An event detector was used to electrically monitor and record failures. Overall, there were 461 failures out of a total of 567 components. The results appear to have a significant amount of variation. Our preliminary conclusion of this study is that, for the components reworked in this study, a qualified rework facility with a capable process can rework Pb-free boards with SnPb solder alloy and create solder joints that have reliability comparable to as-manufactured Pb-free assemblies.
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 | 0.001 |
| 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 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 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".