In-situ characterization of moisture absorption-desorption and hygroscopic swelling behavior of an underfill material

Moisture absorption and hygroscopic swelling behavior of an underfill material were measured in-situ using the sorption TGA and the DMA-RH techniques, respectively. Results showed that moisture diffusion can be well described by Fick's law when the relative humidity (RH) is 60% or less, and the diffusivity exhibits an Arrhenius temperature dependence with an activation energy of ∼ 0.56 eV. At 85% RH, non-Fickian diffusion behavior becomes apparent in the latter stage of the diffusion process. Increase in the saturated moisture content (Csat) at 60%RH was observed after exposure at 85°C 85%RH, which is attributed to hygrothermal ageing induced damage in the material. In-situ DMA-RH results showed that hygroscopic swelling strain is significant comparing with the thermal expansion of the material, and the swelling strain at 60°C 60%RH is equivalent to the thermal strain over a ΔT of 100°C for T < Tg. The coefficient of hygroscopic swelling (CHS) was calculated and the results showed that CHS is temperature dependent, and it increases with the increasing temperature. At higher humidity condition (85%RH or higher), the swelling strain deviates from its linear dependence on Csat and it increases faster than linear when Csat increases, which may also be attributed to hygrothermal ageing induced damage in the underfill material.

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

[2]  Ranjan Rajoo,et al.  The mechanics and impact of hygroscopic swelling of polymeric materials in electronic packaging , 2000, 2000 Proceedings. 50th Electronic Components and Technology Conference (Cat. No.00CH37070).

[3]  Samson Yoon,et al.  Measurement of the Hygroscopic Swelling Coefficient of Thin Film Polymers Used in Semiconductor Packaging , 2010, IEEE Transactions on Components and Packaging Technologies.

[4]  C. Sung,et al.  Characterization of Interaction of Water in Epoxy by UV Reflection Spectroscopy , 2001 .

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

[6]  A. Skipor,et al.  Encapsulation Of Flip Chip Structures , 1992, Thirteenth IEEE/CHMT International Electronics Manufacturing Technology Symposium.

[7]  Zhaowei Zhong,et al.  Reliability assessment and hygroswelling modeling of FCBGA with no-flow underfill , 2003, Microelectron. Reliab..

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

[9]  M. Darby,et al.  Moisture absorption by epoxy resins: The reverse thermal effect , 1990 .

[10]  Yi He,et al.  Thermal characterization of an epoxy-based underfill material for flip chip packaging , 2000 .

[11]  D. Suryanarayana,et al.  Flip-chip solder bump fatigue life enhanced by polymer encapsulation , 1990, 40th Conference Proceedings on Electronic Components and Technology.

[12]  E. Wong,et al.  Swelling and time-dependent subcritical debonding of underfill during temperature-humidity aging of flip chip packages , 2005, IEEE Transactions on Components and Packaging Technologies.

[13]  E. Suhir.  Mechanical behavior and reliability of solder joint interconnections in thermally matched assemblies , 1992, 1992 Proceedings 42nd Electronic Components & Technology Conference.

[14]  Yi He,et al.  Thermomechanical and viscoelastic behavior of a no-flow underfill material for flip-chip applications , 2005 .

[15]  Q. Han,et al.  Experimental investigations and model study of moisture behaviors in polymeric materials , 2009, Microelectron. Reliab..

[16]  G. Johnson,et al.  Water sorption of polycarbonate and its effect on the polymer’s dielectric behavior , 1978 .

[17]  Fei Su,et al.  An optical characterization technique for hygroscopic expansion of polymers and plastic packages , 2006, Microelectron. Reliab..

[18]  Xuejun Fan,et al.  In-situ Characterization of Moisture Absorption and Desorption in a Thin BT Core Substrate , 2007, 2007 Proceedings 57th Electronic Components and Technology Conference.

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

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

[21]  Xuejun Fan,et al.  Moisture Sensitivity of Plastic Packages of IC Devices , 2010 .

[22]  Jianmin Qu,et al.  Elastic modulus variation due to moisture absorption and permanent changes upon redrying in an epoxy based underfill , 2006, IEEE Transactions on Components and Packaging Technologies.

[23]  L. F. Siah.  Moisture-Driven Electromigrative Degradation in Microelectronic Packages , 2010 .

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

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

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

[27]  Jing-en Luan,et al.  Characterization and modeling of hygroscopic swelling and its impact on failures of a flip chip package with no-flow underfill , 2005, 2005 7th Electronic Packaging Technology Conference.

[28]  Seungbae Park,et al.  Temperature dependency of coefficient of hygroscopic swelling of molding compound , 2009, 2009 59th Electronic Components and Technology Conference.

[29]  B. S. Berry,et al.  Bending-cantilever method for the study of moisture swelling in polymers , 1984 .

[30]  Abhijit Mukherjee,et al.  Micromechanics of diffusion-induced damage evolution in reinforced polymers , 2011 .

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

[32]  S. Lee,et al.  Fundamental Characteristics of Moisture Transport, Diffusion, and the Moisture-Induced Damages in Polymeric Materials in Electronic Packaging , 2010 .

[33]  Junjun Wang,et al.  Effect of curing agent polarity on water absorption and free volume in epoxy resin studied by PALS , 2010 .

[34]  T. Y. Tee,et al.  Hygroscopic Swelling of Polymeric Materials in Electronic Packaging: Characterization and Analysis , 2010 .

[35]  Jiming Zhou,et al.  Hygrothermal effects of epoxy resin. Part I: the nature of water in epoxy , 1999 .

[36]  Donald P. Seraphim,et al.  Moisture solubility and diffusion in epoxy and epoxy-glass composites , 1984 .

[37]  Influence of nanosilica on composite underfill properties in flip chip packaging , 2004, 9th International Symposium on Advanced Packaging Materials: Processes, Properties and Interfaces (IEEE Cat. No.04TH8742). 2004 Proceedings..

[38]  I. Ashcroft,et al.  Modelling anomalous moisture uptake, swelling and thermal characteristics of a rubber toughened epoxy adhesive , 2005 .

[39]  Bankim Chandra Ray,et al.  Temperature effect during humid ageing on interfaces of glass and carbon fibers reinforced epoxy composites. , 2006, Journal of colloid and interface science.

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

[41]  G. Gerlach,et al.  Influence of Moisture-Uptake on Mechanical Properties of Polymers Used in Microelectronics , 1998 .

[42]  Ephraim Suhir,et al.  Mechanical Behavior of Flip-Chip Encapsulants , 1990 .

[43]  B. Michel,et al.  Mechanism of Moisture Diffusion, Hygroscopic Swelling, and Adhesion Degradation in Epoxy Molding Compounds , 2010 .

[44]  D. S. Soane,et al.  Water sorption in epoxy thin films , 1989 .

[45]  John Crank,et al.  The Mathematics Of Diffusion , 1956 .

[46]  K. Lu,et al.  Moisture Transport and its Effects on Fracture Strength and Dielectric Constant of Underfill Materials , 2007, 2007 Proceedings 57th Electronic Components and Technology Conference.

[47]  Liu Chen,et al.  The effects of underfill and its material models on thermomechanical behaviors of flip chip package , 2000, International Symposium on Electronic Materials and Packaging (EMAP2000) (Cat. No.00EX458).