Heterogenous Bump Metallurgy Through a Sequential Plating Based Process
Bibliographic record
Abstract
A novel, heterogeneous solder bump structure and means to achieve is proposed. By exploiting a sequential plating process for bump fabrication, a diffusion barrier is placed between solder structures comprising different Ag contents. By controlling the nature and shape of the barrier, a specific structure was derived that successfully maintained a low Ag, ductile solder region proximal to the fragile BEOL of the chip during all solder reflow processes that would occur prior to a reinforcing underfill. A subsequent long dwell reflow step was demonstrated to be capable of breaking the barrier to allow Ag diffusion from the high Ag content region, thus creating a homogeneous interconnect structure with sufficiently high Ag content to encourage high electromigration resistance. The derived temporary structure has the added advantage of ensuring a high aspect ratio, pillar-like solder structure that enables a high-density interconnect design without the use of a stiff Cu structure.
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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 | 0.000 |
| 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 | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".