Research output: Chapter in Book/Conference proceedings/Edited volume › Conference contribution › Scientific › peer-review

**Analytical estimate for cure-induced stresses and warpage in flat packages.** / Jansen, KMB; de Vreugd, J; Ernst, LJ.

Research output: Chapter in Book/Conference proceedings/Edited volume › Conference contribution › Scientific › peer-review

Jansen, KMB, de Vreugd, J & Ernst, LJ 2011, Analytical estimate for cure-induced stresses and warpage in flat packages. in LJ Ernst, GQ Zhang, WDV Driel, P Rodgers, C Bailey & OD Saint Leger (eds), *Proceedings of the 12th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2011, 18-20 April 2011, Linz, Austria.* IEEE Society, Linz, Austria, pp. 1-4, EuroSimE 2011, Linz, Austria, 18/04/11.

Jansen, KMB., de Vreugd, J., & Ernst, LJ. (2011). Analytical estimate for cure-induced stresses and warpage in flat packages. In LJ. Ernst, GQ. Zhang, WD. V. Driel, P. Rodgers, C. Bailey, & O. D. Saint Leger (Eds.), *Proceedings of the 12th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2011, 18-20 April 2011, Linz, Austria *(pp. 1-4). Linz, Austria: IEEE Society.

Jansen KMB, de Vreugd J, Ernst LJ. Analytical estimate for cure-induced stresses and warpage in flat packages. In Ernst LJ, Zhang GQ, Driel WDV, Rodgers P, Bailey C, Saint Leger OD, editors, Proceedings of the 12th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2011, 18-20 April 2011, Linz, Austria. Linz, Austria: IEEE Society. 2011. p. 1-4

@inproceedings{c3a881c7755444ca981a55df19209998,

title = "Analytical estimate for cure-induced stresses and warpage in flat packages",

abstract = "Warpage of flat packages is partly due to chemical shrinkage of the molding compound during cure and partly due to differences in thermal contraction in the subsequent cooling stage. The latter effect is relatively easy to incorporate in numerical simulations but the cureinduced shrinkage effect is not and is therefore often neglected in warpage simulations. Recent validation studies however showed that it is essential that both effects are taken into account. In this paper we develop explicit analytical expressions for the cure-induced residual stresses and warpage of a simple bilayer construction. We do this by assuming that curing always takes place above the molding compounds glass transition temperature such that the material is in its rubbery state and that viscoelastic effects are absent. The analytical warpage model was shown to give results comparable to numerical calculations using a fullly cure dependent viscoelastic material model. Furthermore, for the first time accurate analytical expression for the Stress Free Temperature and Stress Free Strain are obtained. With these expressions the effect of cure shrinkage on residual stresses can easily be incorporated in existing (numerical) stress analyses without the need of using extensive cure dependent viscoelastic material models.",

keywords = "conference contrib. refereed, Conf.proc. > 3 pag",

author = "KMB Jansen and {de Vreugd}, J and LJ Ernst",

year = "2011",

language = "English",

isbn = "978-1-4577-0105-4",

publisher = "IEEE Society",

pages = "1--4",

editor = "LJ Ernst and GQ Zhang and Driel, {WD van} and P Rodgers and C Bailey and {Saint Leger}, {O de}",

booktitle = "Proceedings of the 12th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2011, 18-20 April 2011, Linz, Austria",

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TY - GEN

T1 - Analytical estimate for cure-induced stresses and warpage in flat packages

AU - Jansen, KMB

AU - de Vreugd, J

AU - Ernst, LJ

PY - 2011

Y1 - 2011

N2 - Warpage of flat packages is partly due to chemical shrinkage of the molding compound during cure and partly due to differences in thermal contraction in the subsequent cooling stage. The latter effect is relatively easy to incorporate in numerical simulations but the cureinduced shrinkage effect is not and is therefore often neglected in warpage simulations. Recent validation studies however showed that it is essential that both effects are taken into account. In this paper we develop explicit analytical expressions for the cure-induced residual stresses and warpage of a simple bilayer construction. We do this by assuming that curing always takes place above the molding compounds glass transition temperature such that the material is in its rubbery state and that viscoelastic effects are absent. The analytical warpage model was shown to give results comparable to numerical calculations using a fullly cure dependent viscoelastic material model. Furthermore, for the first time accurate analytical expression for the Stress Free Temperature and Stress Free Strain are obtained. With these expressions the effect of cure shrinkage on residual stresses can easily be incorporated in existing (numerical) stress analyses without the need of using extensive cure dependent viscoelastic material models.

AB - Warpage of flat packages is partly due to chemical shrinkage of the molding compound during cure and partly due to differences in thermal contraction in the subsequent cooling stage. The latter effect is relatively easy to incorporate in numerical simulations but the cureinduced shrinkage effect is not and is therefore often neglected in warpage simulations. Recent validation studies however showed that it is essential that both effects are taken into account. In this paper we develop explicit analytical expressions for the cure-induced residual stresses and warpage of a simple bilayer construction. We do this by assuming that curing always takes place above the molding compounds glass transition temperature such that the material is in its rubbery state and that viscoelastic effects are absent. The analytical warpage model was shown to give results comparable to numerical calculations using a fullly cure dependent viscoelastic material model. Furthermore, for the first time accurate analytical expression for the Stress Free Temperature and Stress Free Strain are obtained. With these expressions the effect of cure shrinkage on residual stresses can easily be incorporated in existing (numerical) stress analyses without the need of using extensive cure dependent viscoelastic material models.

KW - conference contrib. refereed

KW - Conf.proc. > 3 pag

UR - http://www.eurosime.org

M3 - Conference contribution

SN - 978-1-4577-0105-4

SP - 1

EP - 4

BT - Proceedings of the 12th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2011, 18-20 April 2011, Linz, Austria

A2 - Ernst, LJ

A2 - Zhang, GQ

A2 - Driel, WD van

A2 - Rodgers, P

A2 - Bailey, C

A2 - Saint Leger, O de

PB - IEEE Society

CY - Linz, Austria

ER -

ID: 1643703