DocumentCode :
1613109
Title :
Numerical analysis of thermal stresses induced during VFM encapsulant curing
Author :
Tilford, T. ; Sinclair, K.I. ; Goussetis, G. ; Bailey, C. ; Desmulliez, M.P.Y. ; Parrott, A.K. ; Sangster, A.J.
Author_Institution :
Centre for Numerical Modelling & Process Anal. (CNMPA), Univ. of Greenwich, London, UK
fYear :
2008
Firstpage :
348
Lastpage :
353
Abstract :
Encapsulant curing using a Variable Frequency Microwave (VFM) system is analysed numerically. Thermosetting polymer encapsulant materials require an input of heat energy to initiate the cure process. In this article, the heating is considered to be performed by a novel microwave system, able to perform the curing process more rapidly than conventional techniques. Thermal stresses are induced when packages containing materials with differing coefficients of thermal expansion are heated, and cure stresses are induced as thermosetting polymer materials shrink during the cure process. These stresses are developed during processing and remain as residual stresses within the component after the manufacturing process is complete. As residual stresses will directly affect the reliability of the device, it is necessary to assess their magnitude and the effect on package reliability. A coupled multiphysics model has been developed to numerically analyse the microwave curing process. In order to obtain a usefully accurate model of this process, a holistic approach has been taken, in which the process is not considered to be a sequence of discrete steps, but as a complex coupled system. An overview of the implemented numerical model is presented, with particular focus paid to analysis of induced thermal stresses. Results showing distribution of stresses within an idealised microelectronics package are presented and are discussed.
Keywords :
curing; internal stresses; microwave heating; numerical analysis; thermal stresses; VFM encapsulant curing; coupled multiphysics model; cure stresses; heat energy; heating; manufacturing process; microwave curing process; numerical analysis; package reliability; residual stresses; thermal expansion; thermal stresses; thermosetting polymer encapsulant materials; thermosetting polymer materials shrink; variable frequency microwave system; Curing; Electromagnetic heating; Frequency; Numerical analysis; Packaging; Polymers; Rapid thermal processing; Residual stresses; Thermal expansion; Thermal stresses;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electronics Technology, 2008. ISSE '08. 31st International Spring Seminar on
Conference_Location :
Budapest
Print_ISBN :
978-1-4244-3972-0
Electronic_ISBN :
978-1-4244-3974-4
Type :
conf
DOI :
10.1109/ISSE.2008.5276666
Filename :
5276666
Link To Document :
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