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Record W4416880004 · doi:10.37665/jsmtwtpss47010

Process Optimization for 1.0 mm Pitch CBGA

2000· article· W4416880004 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueJournal of Surface Mount Technology · 2000
Typearticle
Language
FieldEngineering
TopicElectronic Packaging and Soldering Technologies
Canadian institutionsIBM (Canada)
Fundersnot available
KeywordsInterconnectionBall grid arraySurface-mount technologyPrinted circuit boardSolderingIntegrated circuit packagingCeramicIntegrated circuitChip-scale packageRanging

Abstract

fetched live from OpenAlex

ABSTRACT The ceramic ball grid array (CBGA) package is used today in a wide range of applications because of its many advantages: high interconnection density; compatibility with standard surface mount technology (SMT) assembly techniques; excellent thermal and electrical performance; and high interconnectivity. Todayís CBGA applications include memory, logic, and microprocessors, and they are found in computer systems ranging from desktop to mainframe with highest usage in work station and server applications. As these applications, particularly the high-end work stations and network servers, demand greater numbers of interconnections, increasing the interconnection density is one means of providing a solution. Decreasing the interconnection pitch on the CBGA package from the typical 1.27 mm to 1.0 mm gives a corresponding increase in interconnection density. This increased density reduces the package body size for the same number of interconnections. For instance, 937 I/O are available on a 32.5 mm package with 1.0 mm pitch, instead of a 42.5 mm package with 1.27 mm pitch (1088 I/O). The smaller body size conserves area on the printed circuit board, but the tighter pitch requires more advanced printed circuit board (PCB) groundrules. The smaller body size, with its reduced distance to neutral point (DNP), should improve the reliability on a per interconnection basis, although the advantage is tempered by a reduction in solder joint height due to a smaller solder ball. The appropriate geometries and process parameters must be chosen, however, for optimum manufacturing yield and reliability. This paper will discuss the process development activities and experiments to determine the optimum structure for the 1.0 mm pitch CBGA package. Elements included in the evaluation are: printed circuit board groundrules, ball diameter and attach processing, solder volumes and other card assembly parameters, and card assembly rework processing. Both yield and reliability are considered in choosing the optimum structure and processes.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: Simulation or modeling
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.207
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0010.001
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.008
GPT teacher head0.245
Teacher spread0.236 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it