In-situ Characterization of Moisture Absorption and Desorption in a Thin BT Core Substrate

Bismaleimide-triazine (BT) resin/glass fiber laminates are commonly used as a substrate core material in microelectronic packaging. Their moisture absorption and diffusion behavior have a significant impact on package reliability. The traditional method to determine moisture absorption relies on a weight gain measurement metrology with an analytical balance. This approach is generally not suitable for thin films. In this study, the moisture absorption-desorption behavior of a thin BT core was characterized in-situ using a sorption TGA over a temperature range of 30 to 80degC, in an environment of up to 80% relative humidity. From the experimental results, the moisture diffusivity and the saturated moisture content have been determined. Within the experimental temperature range, the diffusivity can be described by the Arrhenius equation and the activation energy can be computed. The obtained results are compared with literature data. The impact of moisture diffusion in BT core on the reliability of ultra-thin stacked chip scale packages (UT/SCSP) will be discussed.

[1]  J. Westwater,et al.  The Mathematics of Diffusion. , 1957 .

[2]  G. Springer,et al.  Moisture Absorption and Desorption of Composite Materials , 1976 .

[3]  E. Turi,et al.  Thermal characterization of polymeric materials , 1981 .

[4]  I. Fukuzawa,et al.  Moisture Resistance Degradation of Plastic LSIs by Reflow Soldering , 1985, 23rd International Reliability Physics Symposium.

[5]  V. B. Gupta,et al.  The physical basis of moisture transport in a cured epoxy resin system , 1985 .

[6]  G. J. Dienes,et al.  An Introduction to Solid State Diffusion , 1988 .

[7]  J. Galloway,et al.  Moisture absorption and desorption predictions for plastic ball grid array packages , 1996 .

[8]  Chan Eon Park,et al.  Humidity effects on adhesion strength between solder ball and epoxy underfills , 1997 .

[9]  Michael Pecht,et al.  Moisture ingress into organic laminates , 1999 .

[10]  A. Yee,et al.  Effect of temperature on moisture absorption in a bismaleimide resin and its carbon fiber composites , 2002 .

[11]  Ee-Hua Wong,et al.  Moisture absorption and diffusion characterisation of packaging materials--advanced treatment , 2003, Microelectron. Reliab..

[12]  Jianmin Qu,et al.  Moisture Absorption Analysis of Interfacial Fracture Test Specimens Composed of No-Flow Underfill Materials , 2003 .

[13]  Michael Pecht,et al.  Hygroscopic swelling and sorption characteristics of epoxy molding compounds used in electronic packaging , 2003 .

[14]  M.G. Pecht,et al.  Characterization of hygroscopic swelling behavior of mold compounds and plastic packages , 2004, IEEE Transactions on Components and Packaging Technologies.

[15]  H. Sue,et al.  Micromechanics modeling of moisture diffusion in woven composites , 2005 .

[16]  E.H. Wong,et al.  Correlation of material properties to reliability performance of anisotropic conductive adhesive flip chip packages , 2005, IEEE Transactions on Components and Packaging Technologies.

[17]  Xu Chen,et al.  Moisture sorption-desorption-resorption characteristics and its effect on the mechanical behavior of the epoxy system , 2005 .

[18]  B. Xie,et al.  Sensitivity Investigation of Substrate Thickness and Reflow Profile on Wafer Level Film Failures in 3D Chip Scale Packages by Finite Element Modeling , 2007, 2007 Proceedings 57th Electronic Components and Technology Conference.