NDLI: Analysis and comparison of thermal stress and hygrothermal stress of SiP device by QFN packaging

Content Provider	IEEE Xplore Digital Library
Author	Jiang Haihua Xiao-song Ma Chen Ning
Copyright Year	2008
Description	Author affiliation: Guilin Univ. of Electron. Technol., Guilin (Jiang Haihua; Xiao-song Ma; Chen Ning)
Abstract	In this paper, the model is built by using the SIP structure. The SIP structure is consist of two chips which were using QFN flip-structure. The finite element analysis is used to simulate and calculate the distribution of moisture diffusion under thermal and moisture condition, then to simulate the thermal stress and hygrothermal stress. The results showed that thermal stress are mainly distributed in the mismatch of CTE (coefficient of thermal expansion) between the materials. The largest thermal stress lie in the junction of EMC, DA and chips. We can see that it has a larger thermal effect to the SIP devices used QFN packaging inside than general QPN.The distribution of hygrothermal stress, which is similar as thermal stress in trend, is mainly in mismatch of CTE and CME Coefficient of Moisture induced Expansion. However, moisture gradient, which is caused by structure and the uneven diffusing of moisture become larger. It due to moisture difference that hygrothermal stress is much higher than the thermal stress, its stress concentration appears obviously at the junction between the materials. If the interface of the two materials exist defects, they would lead to cracks and cause the failure of the device. In the area of inside device there is less moisture diffused, its hygrothermal stress distribution is similar to general thermal stress, which is due to moisture transfer firstly through the EMC materials then into the device inside. Moreover, the internal bonding material (DA) is thin, only can absorp moisture from EMC, resulting in only a little moisture can diffuse into the DA material, then cause higher stress gradient. From the simulation results, we can see that the greater stress gradient will lead to warpage of the device, it will prone to more damage in the areas stress concentration. It is larger effect on reliability on SiP device in which used QFN packaging than the general QPN device. Therefore, the effect of EMC and DApsilas moisture on the devicepsilas stress can not be ignored. And the reaults show that the maximum hygrothermal stress is 1.56 times as thermal stress. Therefore, the effect of moistrue and thermal in reliability on the device canpsilat be ignored.
Starting Page	1
Ending Page	5
File Size	1329552
Page Count	5
File Format	PDF
ISBN	9781424427390
DOI	10.1109/ICEPT.2008.4607143
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2008-07-28
Publisher Place	China
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Stress Moisture Electronic packaging thermal management Thermal stresses Materials Electromagnetic compatibility Thermal analysis
Content Type	Text
Resource Type	Article

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