Please wait, while we are loading the content...
| Content Provider | Springer Nature Link |
|---|---|
| Author | Suhir, E. |
| Copyright Year | 2016 |
| Abstract | It is shown, based on the developed analytical predictive model, that a significant thermal stress relief can be achieved in an optimized design of an inhomogeneously bonded bi-material assembly, if its bonding system is designed in such a way that the interfacial shearing stress at the ends of the high-modulus-and-high-bonding-temperature mid-portion of the assembly at its boundary with the low-modulus-and-low-bonding-temperature peripheral portion is made equal to the stress at the assembly ends. The numerical example carried out for such an optimized ball-grid-array (BGA) or a column-grid-array (CGA) electronic assembly indicates that the above measure enables one to design an assembly, in which the induced interfacial stresses are about half of the stresses in a regular, non-optimized, but still inhomogeneously bonded assembly with a low-modulus-and/or-low-bonding-temperature material at its ends. The predicted maximum stress in an optimized assembly is only about 41 % of the maximum stress in a homogeneously bonded BGA assembly and about 46 % of the maximum stress in a homogeneously bonded CGA assembly. The numerical data indicated also that the application of the CGA technology in a non-optimized inhomogeneously bonded assembly enables one to achieve a 19 % stress relief in the case of an application of the epoxy adhesive at the peripheral portions of the assembly, and that a 34 % stress relief could be expected in the case of the use of a low modulus solder at the assembly ends. When a BGA technology is considered, the application of an epoxy or a low modulus solder at the peripheral portions of the assembly leads to approximately the same stress relief effect: about 14 % in the case of an epoxy adhesive and about 13 % in the case of a low modulus solder. When a CGA technology is considered, the application of an epoxy at the peripheral portions of the non-optimized assembly leads to about 9.0 % stress relief, while the application of a low modulus solder results in about 24 % stress relief. If, e.g., the yield stress in shear is 1.85 kg/mm$^{2}$ for the solder in the assembly’s mid-portion and 1.35 kg/mm$^{2}$ for the peripheral solder material, the application of the CGA technology in combination with an inhomogeneous bond with an epoxy adhesive or a low modulus solder at the assembly ends might enable one to avoid inelastic strains in the solder, weather in the mid-portion or in the peripheral portion, thereby increasing dramatically the fatigue lifetime of the bond. It is even easier to achieve this goal with the use of the suggested optimized design of an inhomogeneous bond. |
| Starting Page | 5563 |
| Ending Page | 5574 |
| Page Count | 12 |
| File Format | |
| ISSN | 09574522 |
| Journal | Journal of Materials Science: Materials in Electronics |
| Volume Number | 27 |
| Issue Number | 6 |
| e-ISSN | 1573482X |
| Language | English |
| Publisher | Springer US |
| Publisher Date | 2016-02-16 |
| Publisher Place | New York |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Optical and Electronic Materials Characterization and Evaluation of Materials |
| Content Type | Text |
| Resource Type | Article |
| Subject | Atomic and Molecular Physics, and Optics Biomaterials Biophysics Condensed Matter Physics Electronic, Optical and Magnetic Materials Bioengineering Electrical and Electronic Engineering Biomedical Engineering |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|