Effect of Moisture on the Interfacial Adhesion of the Underfill/Solder Mask Interface

Ferguson, Timothy P.; Qu, Jianmin

doi:10.1115/1.1414133

Cited by 35 publications

(18 citation statements)

References 6 publications

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“…The residual stress at the interface in the encapsulated package is induced due to the CTE mismatch [42] and the cure shrinkage of EMC [43] when it is cooled down from molding temperature to room temperature. Furthermore, it seems that the interface adhesion is a function of exposure time to moisture and the adhesion strength decreases as the moisture content increases [44,45]. Finally, the moisture diffusion coefficient at the EMC/leadframe interface is larger (almost one order magnitude) than that in the bulk EMC which may be due to the large pore sizes at the EMC/ leadframe interface than those within the bulk EMC and also capillary diffusion along the EMC/leadframe interface [46,47].…”

Section: Variation Of Stress Intensity Factor and Strain Energy Releamentioning

confidence: 93%

Interface delamination analysis of TQFP package during solder reflow

Rossi

Luan

et al. 2010

Microelectronics Reliability

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Section: Variation Of Stress Intensity Factor and Strain Energy Releamentioning

confidence: 93%

Interface delamination analysis of TQFP package during solder reflow

Rossi

Luan

et al. 2010

Microelectronics Reliability

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“…A number of effects result from the ingress of liquid into an adhesive joint, including plasticization of the polymeric adhesive and disruption of the interfacial region between the substrate and the organic phase [30]. X-ray photoelectron spectroscopy (XPS) surface analyses of wedge test specimens that were preconditioned in cyan ink vehicle and DI water were carried out to determine the mode of failure.…”

Section: Figure 14mentioning

confidence: 99%

Subcritical Delamination in Epoxy Bonds to Silicon and Glass Adherends: Effect of Temperature and Preconditioning

Singh

Wan

Dillard

et al. 2008

The Journal of Adhesion

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The effects of temperature and preconditioning in deionized (DI) water and a cyan ink vehicle used in inkjet printer cartridges on the durability of glass=epoxy and silicon=epoxy systems have been investigated. A test matrix consisting of test temperatures, preconditioning temperatures, preconditioning times, and nature of adherends and adhesives was developed and a series of experiments was conducted using wedge test specimens (glass or silicon coupons bonded with epoxy) to investigate the subcritical adhesion performance of the glass=epoxy and silicon=epoxy interfaces. The glass=epoxy and silicon=epoxy interfaces were found to be relatively insensitive to temperature over a range of 22-60 , but significant temperature effects, more complex than suggested by time-temperature superposition (TTSP), were observed above 60 C, depending on the environmental chemistry and nature of the adhesive used.Specimens made of silicon coupons bonded with epoxy were subjected to preconditioning in DI water and the cyan ink vehicle prior to wedge insertion to study the effect of prior environmental exposure. The wedge test data from preconditioned specimens were compared with standard wedge test results and the Si=epoxy interface was found to be insensitive to preconditioning in DI water but was affected significantly by preconditioning in the cyan ink vehicle. Plots of crack velocity versus applied strain energy release rate for particular sets of environmental conditions are presented and a comparison is made for different environmental conditions to quantify the subcritical debonding behavior of systems studied.

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“…This approach is suitable to describe the reported measurements of moisture absorption [20,27,28,30,31,34]. The model can only be applied up to maximum periods comparable to those discussed in this paper.…”

Section: Introductionmentioning

confidence: 97%

“…According to eqn. 2, N would reach a saturation over time, whereas a slow and steady increase in absorbed moisture is observed for epoxies and polyimides even after longer periods [20,27,28,30]. Two types of water, mobile and immobilized water, have been detected by various methods like infrared spectroscopy, ultraviolet spectroscopy and dielectric measurements [31][32][33].…”

Section: Introductionmentioning

confidence: 98%

Rapid Interface Reliability Testing of Flip Chip Encapsulants

Rau¹,

Becker

Wunderle

et al. 2007

2007 Proceedings 57th Electronic Components and Technology Conference

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A rapid interface reliability test for underfill materials in real flip chip on board assemblies consisting of autoclave aging at 121PC and 100% relative humidity, followed by vibrational stressing at room temperature has been developed. The moisture concentrations in the flip chip assembly have been calculated by Finite Element Simulations to determine an adequate autoclave aging period. An extended three parameter diffusion model based on Fick's law has been used. It considers an additional first order binding of the moisture and enables the modeling of a linear moisture absorption beyond the fickian saturation level, as observed for epoxies and polyimides. The diffusion properties and the adhesion of the underfiller are tested by the subsequent vibrational stressing. The results of linear-elastic finite element simulations show, that the vibrational test induces the same shear stresses and strains in the underfill material as those induced by the mismatch of the coefficient of thermal expansion (CTE) between board and chip in temperature cycling. However the CTE mismatch between underfill and its adjacent materials causes additional tensile stress and strain during temperature cycling, which are not induced by the vibrational test. Thus the rapid interface test is independent of the thermo-mechanical properties of the underfill material. It enables a fast selection of underfill materials with good adhesion in a humid environment, which suit applications in harsh environments. By using a defined test setup, in which only the underfill material is varied, the assessment period is reduced to less than a week. The advantage compared to standard material testing procedures is the use of a real flip chip assembly. Thus the materials are tested in the relevant dimensions and combinations processed in a manufacturing assembly flow.

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Effect of Moisture on the Interfacial Adhesion of the Underfill/Solder Mask Interface

Cited by 35 publications

References 6 publications

Interface delamination analysis of TQFP package during solder reflow

Interface delamination analysis of TQFP package during solder reflow

Subcritical Delamination in Epoxy Bonds to Silicon and Glass Adherends: Effect of Temperature and Preconditioning

Rapid Interface Reliability Testing of Flip Chip Encapsulants

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