| Project/Area Number |
09555028
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Yokohama National University |
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Principal Investigator |
SHIRATORI Masaki Yokohama National University, Faculty of Engineering, Professor, 工学部, 教授 (60017986)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Hayato JT Toshi Inc., 技術本部, 本部長(研究職)
OKUMOTO Hiroshi Japan Tobacco Inc..Machinery Enterprise Division, Senior vice president, 機械事業部, 部長(研究職)
OGASAWARA Nagahisa Yokohama National University, Faculty of Engineering, Research associate, 工学部, 助手 (60262408)
YU Qiang Yokohama National University, Faculty of Engineering, Assistant professor, 工学部, 助教授 (80242379)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥13,700,000 (Direct Cost: ¥13,700,000)
Fiscal Year 1998: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1997: ¥10,100,000 (Direct Cost: ¥10,100,000)
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| Keywords | micro structure / material testing machine / thermal fatigue / estimation of fatigue life / stress-strain estimation |
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| Research Abstract |
With the increasing need for high mount density, the BGA (Ball Grid Array) or CSP (Chip Size Package) soldering became the main trend of the electronics mount technology. As a result, the evaluation of the fatigue life of BGA solder joints is one of the most important problems to study the reliability of BGA packages. In this study, a micro-displacement and low load fatigue tester for the micro-structures was developed. Using the tester, the fatigue life of BGA CSP solder joints was studied, and fatigue reliability assessment method was established.
The results of this study are shown as follows ;
(1) A new testing machine suitable for fatigue testing for the micro-structures such as BOA or CSP solder joints was proposed, by utilizing a piezoelectric translator (PZT) for the main push/pull actuator and twin PZTs for measuring the load without dislocation.
(2) Based upon the proposed concept, a new fatigue tester was developed.
(3) Using this tester, the fatigue lire of BGA CSP solder joints were investigated, and the results of fatigue tests were used to develop a fatigue reliability assessment method for all kinds of BOA solder joints. Furthermore, three-dimensional FEA were carried out to get the associated fracture parameter, inelastic equivalent strain range. Based upon the experimental and analytical results, an estimation criterion for fatigue life of the solder joints was developed.
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