Thermal stress induced failures in adhesive flip chip joints

Outi Rusanen, Jaakko Lenkkeri

Research output: Contribution to journalArticleScientificpeer-review

Abstract

In order to estimate the reliability of adhesive Flip Chip joints, four different isotropically conductive adhesives (ICAs) on alumina and FR-4 substrates were subjected to thermal cycling tests (-40 °C — + 125 °C). By fitting the failure rate data to Weibull distribution, the number of cycles leading to 50 percent probability of failure (N f50) was estimated. For test structures on alumina substrates, the estimated N f50 varied between 2500 and 7000 cycles, whereas for test structures on FR-4 substrates, N f50 varied between 360 and 870 cycles, depending on the adhesive used. The stresses and strains in an adhesive joint during a temperature cycle were estimated using a previously developed simulation model, which calculates the stress and the creep strain (c cr) in the viscoelastic ICA material. The results of the simulations together with the testing data were used to find a relationship between N f50 and creep strain range (Dc cr) for adhesive joints. The results for the test structures on alumina substrates seem to obey a Coffin-Manson type relationship, N f50 = C • (Dc cr) h , where C and g have values of 97.5 and –1.15, respectively. The test structures on FR-4, however, showed failures at much lower cycle numbers than could be expected using this equation. The reason for this is the different failure mecha-nism in these samples. The initial cause of failure was not in the adhesive joints but in the underfill delamination.
Original languageEnglish
Pages (from-to)363-369
Number of pages7
JournalJournal of Microelectronics and Electronic Packaging
Volume22
Issue number4
Publication statusPublished - 1999
MoE publication typeA1 Journal article-refereed

Fingerprint

Thermal stress
Adhesive joints
Aluminum Oxide
Adhesives
Alumina
Substrates
Creep
Weibull distribution
Thermal cycling
Delamination
Testing
Temperature

Cite this

Rusanen, Outi ; Lenkkeri, Jaakko. / Thermal stress induced failures in adhesive flip chip joints. In: Journal of Microelectronics and Electronic Packaging. 1999 ; Vol. 22, No. 4. pp. 363-369.
@article{d51cbca7a7d743fd9934052316d1cdac,
title = "Thermal stress induced failures in adhesive flip chip joints",
abstract = "In order to estimate the reliability of adhesive Flip Chip joints, four different isotropically conductive adhesives (ICAs) on alumina and FR-4 substrates were subjected to thermal cycling tests (-40 °C — + 125 °C). By fitting the failure rate data to Weibull distribution, the number of cycles leading to 50 percent probability of failure (N f50) was estimated. For test structures on alumina substrates, the estimated N f50 varied between 2500 and 7000 cycles, whereas for test structures on FR-4 substrates, N f50 varied between 360 and 870 cycles, depending on the adhesive used. The stresses and strains in an adhesive joint during a temperature cycle were estimated using a previously developed simulation model, which calculates the stress and the creep strain (c cr) in the viscoelastic ICA material. The results of the simulations together with the testing data were used to find a relationship between N f50 and creep strain range (Dc cr) for adhesive joints. The results for the test structures on alumina substrates seem to obey a Coffin-Manson type relationship, N f50 = C • (Dc cr) h , where C and g have values of 97.5 and –1.15, respectively. The test structures on FR-4, however, showed failures at much lower cycle numbers than could be expected using this equation. The reason for this is the different failure mecha-nism in these samples. The initial cause of failure was not in the adhesive joints but in the underfill delamination.",
author = "Outi Rusanen and Jaakko Lenkkeri",
year = "1999",
language = "English",
volume = "22",
pages = "363--369",
journal = "Journal of Microelectronics and Electronic Packaging",
issn = "1551-4897",
publisher = "IMAPS-International Microelectronics and Packaging Society",
number = "4",

}

Thermal stress induced failures in adhesive flip chip joints. / Rusanen, Outi; Lenkkeri, Jaakko.

In: Journal of Microelectronics and Electronic Packaging, Vol. 22, No. 4, 1999, p. 363-369.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Thermal stress induced failures in adhesive flip chip joints

AU - Rusanen, Outi

AU - Lenkkeri, Jaakko

PY - 1999

Y1 - 1999

N2 - In order to estimate the reliability of adhesive Flip Chip joints, four different isotropically conductive adhesives (ICAs) on alumina and FR-4 substrates were subjected to thermal cycling tests (-40 °C — + 125 °C). By fitting the failure rate data to Weibull distribution, the number of cycles leading to 50 percent probability of failure (N f50) was estimated. For test structures on alumina substrates, the estimated N f50 varied between 2500 and 7000 cycles, whereas for test structures on FR-4 substrates, N f50 varied between 360 and 870 cycles, depending on the adhesive used. The stresses and strains in an adhesive joint during a temperature cycle were estimated using a previously developed simulation model, which calculates the stress and the creep strain (c cr) in the viscoelastic ICA material. The results of the simulations together with the testing data were used to find a relationship between N f50 and creep strain range (Dc cr) for adhesive joints. The results for the test structures on alumina substrates seem to obey a Coffin-Manson type relationship, N f50 = C • (Dc cr) h , where C and g have values of 97.5 and –1.15, respectively. The test structures on FR-4, however, showed failures at much lower cycle numbers than could be expected using this equation. The reason for this is the different failure mecha-nism in these samples. The initial cause of failure was not in the adhesive joints but in the underfill delamination.

AB - In order to estimate the reliability of adhesive Flip Chip joints, four different isotropically conductive adhesives (ICAs) on alumina and FR-4 substrates were subjected to thermal cycling tests (-40 °C — + 125 °C). By fitting the failure rate data to Weibull distribution, the number of cycles leading to 50 percent probability of failure (N f50) was estimated. For test structures on alumina substrates, the estimated N f50 varied between 2500 and 7000 cycles, whereas for test structures on FR-4 substrates, N f50 varied between 360 and 870 cycles, depending on the adhesive used. The stresses and strains in an adhesive joint during a temperature cycle were estimated using a previously developed simulation model, which calculates the stress and the creep strain (c cr) in the viscoelastic ICA material. The results of the simulations together with the testing data were used to find a relationship between N f50 and creep strain range (Dc cr) for adhesive joints. The results for the test structures on alumina substrates seem to obey a Coffin-Manson type relationship, N f50 = C • (Dc cr) h , where C and g have values of 97.5 and –1.15, respectively. The test structures on FR-4, however, showed failures at much lower cycle numbers than could be expected using this equation. The reason for this is the different failure mecha-nism in these samples. The initial cause of failure was not in the adhesive joints but in the underfill delamination.

M3 - Article

VL - 22

SP - 363

EP - 369

JO - Journal of Microelectronics and Electronic Packaging

JF - Journal of Microelectronics and Electronic Packaging

SN - 1551-4897

IS - 4

ER -