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

2002 ◽  
Vol 124 (2) ◽  
pp. 106-110 ◽  
Author(s):  
Timothy Ferguson ◽  
Jianmin Qu
Keyword(s):  
Fracture Toughness ◽  
Interfacial Adhesion ◽  
Interfacial Fracture ◽  
Interfacial Fracture Toughness ◽  
Interfacial Toughness ◽  
Solder Mask ◽  
Effect Of Moisture ◽  
Point Bend ◽  
Four Point Bend Test

Moisture poses a significant threat to the reliability of microelectronic assemblies and can be attributed as being the principal cause of many premature package failures. Of particular concern is characterizing the role of moisture with respect to the acceleration of the onset of package delamination. In this paper the effect of moisture on the interfacial fracture toughness of two no-flow underfill materials with a commercially available solder mask coated FR-4 board is experimentally determined. Bilayer specimens with prefabricated interface cracks are used in a four-point bend test to quantify the interfacial fracture toughness. Two groups of test specimens of varying underfill thickness were constructed. The first group was fully dried while the other was moisture preconditioned at 85°C/85%RH for 725 hours. The results of this study show that the interfacial toughness is significantly affected by the presence of moisture.

Effect of Moisture on the Elastic Modulus and Interfacial Adhesion of Polymer-Metal Components in Microelectronic Assemblies

2003 ◽  
Author(s):  
Timothy P. Ferguson ◽  
Jianmin Qu
Keyword(s):  
Fracture Toughness ◽  
Elastic Modulus ◽  
Interfacial Adhesion ◽  
Interfacial Fracture ◽  
Moisture Diffusivity ◽  
Bending Test ◽  
Interfacial Fracture Toughness ◽  
Moisture Concentration ◽  
Polymer Metal ◽  
Effect Of Moisture

Moisture poses a significant threat to the reliability of microelectronic assemblies and can be attributed as being one of the principal causes of many premature package failures. It is a multi-dimensional concern in electronic packaging, having an adverse effect on package reliability by changing both the mechanical properties and interfacial adhesion of the microelectronic assembly. In this paper, a study has been conducted to evaluate the moisture-induced degradation of both the elastic modulus of a commercially available no-flow underfill and the interfacial adhesion of the underfill to a copper alloy substrate. Three different levels of moisture preconditioning, 85C/50%RH, 85C/65%RH, and 85C/85RH%, were implemented in this study. Diffusion coefficient test specimens were constructed to experimentally measure the moisture diffusivity into the underfill resin and obtain the moisture saturation concentration for each level of moisture preconditioning. Flexural bend test specimens were made to characterize the effect of moisture on the elastic modulus of the underfill adhesive. Last, interfacial fracture toughness specimens with prefabricated interface cracks were used in a four point bending test to quantify the effect of moisture on interfacial fracture toughness. The results of this study will aid in the development of more robust microelectronic assemblies, demonstrating how both the elastic modulus and interfacial toughness change as a function of moisture concentration.

Two Test Specimens for Determining the Interfacial Fracture Toughness in Flip-Chip Assemblies

1998 ◽  
Vol 120 (2) ◽  
pp. 150-155 ◽  
Author(s):  
X. Yan ◽  
R. K. Agarwal
Keyword(s):  
Fracture Toughness ◽  
Critical Loads ◽  
Flip Chip ◽  
Interfacial Strength ◽  
Interfacial Fracture ◽  
Circuit Board ◽  
Interfacial Fracture Toughness ◽  
Edge Cracks ◽  
Solder Mask ◽  
Point Bend

Two test specimens are developed to measure interfacial fracture toughness in flip-chip assemblies. The specimens consist of three layers: silicon chip, underfill, and circuit board. Two symmetric edge cracks are embedded along the interface, either between the chip and the underfill or between the underfill and the circuit board. The specimens are subjected to four-point-bend loading and critical loads are obtained. Analytical solutions for energy release rate have been derived for these two specimens and used to obtain the toughness from the measured critical loads. These specimens have been used to evaluate material combinations of chip passivation, underfill and solder mask for desired interfacial strength.

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

2000 ◽  
Author(s):  
Timothy P. Ferguson ◽  
Jianmin Qu
Keyword(s):  
Interfacial Adhesion ◽  
Bending Test ◽  
Primary Concern ◽  
Polymer Interfaces ◽  
Interfacial Toughness ◽  
Four Point Bending ◽  
Four Point Bending Test ◽  
Effect Of Moisture ◽  
Package Reliability

Abstract A primary concern in microelectronic packaging is the role of moisture induced failure mechanisms. Moisture is a multidimensional concern in packaging, having an adverse effect on package reliability by introducing corrosion, development of hygro-stresses, and deterioration of polymer interfaces within the package. In this paper the effect of moisture on the interfacial adhesion of two no flow underfill materials with a commercially available soldermask coated FR-4 board is experimentally determined. Bilayer specimens with prefabricated interface cracks are used in a four point bending test to quantify the interfacial fracture toughness. Two groups of test specimens of varying underfill thickness were constructed. The first group was fully dried while the other was moisture preconditioned at 85°C/85%RH for 725 hours. The results of this study show that the interfacial toughness is significantly affected by the presence of moisture.

scholarly journals Apparent Interfacial Fracture Toughness of Resin/Ceramic Systems

2006 ◽  
Vol 85 (11) ◽  
pp. 1037-1041 ◽  
Author(s):  
A. Della Bona ◽  
K.J. Anusavice ◽  
J.J. Mecholsky
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Interfacial Fracture ◽  
Crack Size ◽  
Interfacial Fracture Toughness ◽  
Critical Crack ◽  
Interfacial Toughness ◽  
Microtensile Test ◽  
Ceramic Microstructure ◽  
Critical Crack Size

We suggest that the apparent interfacial fracture toughness (KA) may be estimated by fracture mechanics and fractography. This study tested the hypothesis that the KA of the adhesion zone of resin/ceramic systems is affected by the ceramic microstructure. Lithia disilicate-based (Empress2-E2) and leucite-based (Empress-E1) ceramics were surface-treated with hydrofluoric acid (HF) and/or silane (S), followed by an adhesive resin. Microtensile test specimens (n = 30; area of 1 ± 0.01 mm2) were indented (9.8 N) at the interface and loaded to failure in tension. We used tensile strength (σ) and the critical crack size (c) to calculate KA (KA = Yσc1/2) (Y = 1.65). ANOVA and Weibull analyses were used for statistical analyses. Mean KA (MPa·m1/2) values were: (E1HF) 0.26 ± 0.06; (E1S) 0.23 ± 0.06; (E1HFS) 0.30 ± 0.06; (E2HF) 0.31 ± 0.06; (E2S) 0.13 ± 0.05; and (E2HFS) 0.41 ± 0.07. All fractures originated from indentation sites. Estimation of interfacial toughness was feasible by fracture mechanics and fractography. The KA for the systems tested was affected by the ceramic microstructure and surface treatment.

A Technique to Measure Interfacial Toughness Over a Range of Phase Angles

1999 ◽  
Vol 122 (2) ◽  
pp. 147-151 ◽  
Author(s):  
Adam Kuhl ◽  
Jianmin Qu
Keyword(s):  
Fracture Toughness ◽  
Interfacial Fracture ◽  
Interfacial Fracture Toughness ◽  
Adhesive Systems ◽  
Adhesive Material ◽  
Element Analysis ◽  
Interfacial Toughness ◽  
Loading Direction ◽  
Wide Range ◽  
Phase Angles

An experimental technique using sandwiched Brazil-nut specimens to quantitatively characterize interfacial fracture toughness over a wide range of phase angles is presented. Specimens are made by sandwiching a thin layer of adhesive material between two metal substrates. Tensile loads are applied to the specimens at various loading angles. Through the use of fracture mechanics and finite element analysis, interfacial fracture toughness as a function of loading phase angle is determined from the experimentally obtained critical load and loading direction. The fracture toughness curves for several different Cu/adhesive systems are obtained. [S1043-7398(00)00302-9]

scholarly journals Evaluation of the Interfacial Fracture Toughness of Anodic Bonds

2007 ◽  
Vol 73 (735) ◽  
pp. 1266-1272 ◽  
Author(s):  
Yoshiaki NOMURA ◽  
Masaki NAGAI ◽  
Toru IKEDA ◽  
Noriyuki MIYAZAKI
Keyword(s):  
Fracture Toughness ◽  
Interfacial Fracture ◽  
Interfacial Fracture Toughness
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