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Flip Chip Process by Using the Cu-Sn-Cu Sandwich Joint Structure of the Cu Pillar Bumps (Cu pillar 범프의 Cu-Sn-Cu 샌드위치 접속구조를 이용한 플립칩 공정)

Choi, Jung-Yeol;Oh, Tae-Sung
- Journal of the Microelectronics and Packaging Society
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- v.16 no.4
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- pp.9-15
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- 2009
Compared to the flip-chip process using solder bumps, Cu pillar bump technology can accomplish much finer pitch without compromising stand-off height. Flip-chip process with Cu pillar bumps can also be utilized in radio-frequency packages where large gap between a chip and a substrate as well as fine pitch interconnection is required. In this study, Cu pillars with and without Sn caps were electrodeposited and flip-chip-bonded together to form the Cu-Sn-Cu sandwiched joints. Contact resistances and die shear forces of the Cu-Sn-Cu sandwiched joints were evaluated with variation of the height of the Sn cap electrodeposited on the Cu pillar bump. The Cu-Sn-Cu sandwiched joints, formed with Cu pillar bumps of $25-{\mu}m$ diameter and $20-{\mu}m$ height, exhibited the gap distance of $44{\mu}m$ between the chip and the substrate and the average contact resistance of $14\;m{\Omega}$/bump without depending on the Sn cap height between 10 to $25\;{\mu}m$.
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A Study on the Implementation of a Community-based LIS Capstone Course: Developing the 21st Century Skills of Preservice Librarians through Human Library Projects (지역사회협력 기반 문헌정보학 캡스톤 교과목 개발과 운영에 관한 연구 - 휴먼라이브러리 프로젝트 수행을 통한 21세기 학습 기술 강화를 중심으로 -)

Jisue Lee
- Journal of the Korean Society for Library and Information Science
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- v.57 no.2
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- pp.379-408
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- 2023
This case study reports on the redevelopment of a course, Local Culture Information Theory offered by the Department of Library and Information Science at C University, into a capstone design course using a project-based learning approach. In collaboration with a local community youth organization, the redesigned course provided an opportunity for LIS students to develop and implement a digital literacy program that enabled high school students to use a variety of digital multimedia technologies to complete a project of digital Human Library featuring video, audio, and digital are such as webtoons. Through semi-structured interviews with 5 students and 3 staff from partner organizations, this study reports on course development process, the establishment of local partnerships, project outcome, as well as suggestions for improvements. In addition, a qualitative analysis of the participating students' interview responses using the Framework for 21st Century Learning (P21) found they developed and improved 11 skills across three core areas: life and career skills including self-direction, project management, collaboration with diverse teams, flexibility, responsibility, leadership; learning and innovation skills including communication and collaboration, problem-solving, creativity, and critical thinking; and information, media, and technology skills through media creation. Lessons learned and recommendations from this case study may be useful for other LIS programs and faculty interested in implementing project-based learning or developing capstone design courses.
https://doi.org/10.4275/KSLIS.2023.57.2.379 인용 PDF