On the effects of temperature on the drop reliability of electronic component boards

Abstract The effects of package temperature on failure mechanisms and lifetimes under mechanical shock loading were studied with the help of five different types of high-density packages (a WL-CSP and four CSP-BGAs) assembled on both double-layer and multi-layer FR4 boards. The localized heating of the packages by means of integrated heating elements was utilized in order to produce similar hot spots to those occurring in products in service. The results showed that the temperature can have a significant effect on the lifetimes of component boards under mechanical shock loading but that the effect varied according to the structures of the component boards. The average number of drops to failure of the WL-CSP component boards increased significantly with an increase in the temperature of the package, while the average number of drops to failure of the CSP-BGA component boards generally decreased. On the other hand, the drop reliability of one out of four CSP-BGA component board types was insensitive to temperature. The failure modes and mechanisms were clarified with the help of physical failure analyses that revealed different failure modes in the component boards. Furthermore, depending on the component board type, the primary failure mode may change with temperature from that identified at room temperature. Particular attention was paid to the nucleation and propagation of cracks at different test temperatures. Computational case studies were designed in order to identify the significance of a change in temperature on three factors: (a) the stiffness of the PWB; (b) the strength and elastic modulus of the solder, and (c) the thermomechanical loads. The influences of each factor on the strains and stresses in the proximity of the solder interconnections were evaluated by means of the finite element method. The results of the statistical and physical failure analyses were rationalized with the help of the results from the finite element analyses. They showed that the effects of a change in temperature on the lifetimes of the component boards under mechanical shock loading can be explained by changes in the nucleation site and/or the propagation of cracks. The results presented in this paper point out that single-load reliability tests can form an incomplete understanding of the failure mechanisms in real service environments and modifications to the currently employed reliability test standards that are needed.

[1]  J.S. Karppinen,et al.  Formation of thermomechanical interconnection stresses in a high-end portable product , 2008, 2008 2nd Electronics System-Integration Technology Conference.

[2]  John H. L. Pang,et al.  Drop Impact Reliability Testing for Lead-Free and Leaded Soldered IC Packages , 2005, Proceedings Electronic Components and Technology, 2005. ECTC '05..

[3]  J.K. Kivilahti,et al.  Failure Modes of Solder Interconnections under Mechanical Shock Loading at Elevated Temperatures , 2006, 2006 1st Electronic Systemintegration Technology Conference.

[4]  Willem D. van Driel,et al.  Advances in the drop-impact reliability of solder joints for mobile applications , 2009, Microelectron. Reliab..

[5]  Vesa Vuorinen,et al.  Interfacial reactions between lead-free SnAgCu solder and Ni(P) surface finish on printed circuit boards , 2002 .

[6]  Pradeep Lall,et al.  The effects of SAC alloy composition on aging resistance and reliability , 2009, 2009 59th Electronic Components and Technology Conference.

[7]  P. Marjamaki,et al.  Deformation characteristics and microstructural evolution of SnAgCu solder joints , 2005, EuroSimE 2005. Proceedings of the 6th International Conference on Thermal, Mechanial and Multi-Physics Simulation and Experiments in Micro-Electronics and Micro-Systems, 2005..

[8]  P. Marjamaki,et al.  Reliability of CSP Interconnections Under Mechanical Shock Loading Conditions , 2006, IEEE Transactions on Components and Packaging Technologies.

[9]  J. Suhling,et al.  A review of mechanical properties of lead-free solders for electronic packaging , 2009, Journal of Materials Science.

[10]  Xinjun Sheng,et al.  Reliability study of board-level lead-free interconnections under sequential thermal cycling and drop impact , 2009, Microelectron. Reliab..

[11]  Pjtl Pascal Oberndorff.  Lead-free solder systems : phase relations and microstructures , 2001 .

[12]  Ephraim Suhir,et al.  Micro- and opto-electronic materials and structures : physics, mechanics, design, reliability, packaging , 2007 .

[13]  L. Nguyen,et al.  Effect of Temperature on the Drop Reliability of Wafer-Level Chip Scale Packaged Electronics Assemblies , 2007, 2007 Proceedings 57th Electronic Components and Technology Conference.

[14]  C. Basaran,et al.  Experimental damage mechanics of microelectronic solder joints under fatigue loading , 2004, Proceedings Electronic Components and Technology, 2005. ECTC '05..

[15]  J. W. Meredith,et al.  Microelectronics reliability , 1988, IEEE Region 5 Conference, 1988: 'Spanning the Peaks of Electrotechnology'.

[16]  M. Amagai,et al.  High drop test reliability: lead-free solders , 2004, 2004 Proceedings. 54th Electronic Components and Technology Conference (IEEE Cat. No.04CH37546).

[17]  Luke Garner,et al.  Finding Solutions to the Challenges in Package Interconnect Reliability , 2005 .

[18]  P. Marjamäki.  Vibration test as a new method for studying the mechanical reliability of solder interconnections under shock loading conditions , 2007 .

[19]  K. N. Subramanian,et al.  Effects of intermetallic morphology at the metallic particle/solder interface on mechanical properties of Sn-Ag-based solder joints , 2003 .

[20]  Jorma Kivilahti,et al.  Failure mechanisms of lead-free chip scale package interconnections under fast mechanical loading , 2005 .

[21]  T. Mattila,et al.  Reliability of lead-free interconnections under consecutive thermal and mechanical loadings , 2006 .

[22]  R. Darveaux,et al.  Mechanical Properties of Lead-Free Solders , 2007, 2007 Proceedings 57th Electronic Components and Technology Conference.

[23]  J. Kivilahti,et al.  Intermetallic reactions between lead-free SnAgCu solder and Ni(P)/Au surface finish on PWBs , 2001, 2001 Proceedings. 51st Electronic Components and Technology Conference (Cat. No.01CH37220).

[24]  Hong Tang,et al.  Experimental characterization of material degradation of solder joint under fatigue loading , 2002, ITherm 2002. Eighth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (Cat. No.02CH37258).

[25]  F. Che,et al.  Impact of Thermal Cycling on Sn-Ag-Cu Solder Joints and Board-Level Drop Reliability , 2008 .

[26]  T. Laurila,et al.  Metallurgical factors behind the reliability of high density lead-free interconnections , 2006 .

[27]  A. Syed,et al.  Reliability of SnAgCu Interconnections with Minor Additions of Ni or Bi under Mechanical Shock Loading at Different Temperatures , 2007, 2007 Proceedings 57th Electronic Components and Technology Conference.

[28]  W. Peng,et al.  Effect of Thermal Aging on Drop Performance of Chip Scale Packages with SnAgCu Solder Joints on Cu Pads , 2007 .

[29]  M. Pecht,et al.  The Role of Aging on Dynamic Failure Envelopes of OSP-Sn37Pb Interconnects in Plastic Ball Grid Array (PBGA) Packages , 2009, IEEE Transactions on Components and Packaging Technologies.

[30]  T. Mattila,et al.  Replacement of the drop test with the vibration test — The effect of test temperature on reliability , 2008, 2008 58th Electronic Components and Technology Conference.

[31]  M. Tanaka,et al.  Improvement in drop shock reliability of Sn-1.2Ag-0.5Cu BGA interconnects by Ni addition , 2006, 56th Electronic Components and Technology Conference 2006.

[32]  M. Amagai.  A study of nanoparticles in SnAg-based lead free solders for intermetallic compounds and drop test performance , 2006, 56th Electronic Components and Technology Conference 2006.

[33]  Toni T. Mattila,et al.  Reliability of Electronic Assemblies Under Mechanical Shock Loading , 2011 .

[34]  T. Laurila,et al.  Solid-State Reactions between Cu(Ni) Alloys and Sn , 2007 .

[35]  T. Mattila,et al.  Impact of printed wiring board coatings on the reliability of lead-free chip-scale package interconnections , 2004 .

[36]  M. Dusek,et al.  The impact of thermal cycling regime on the shear strength of lead‐free solder joints , 2005 .

[37]  T. Chiu,et al.  Effect of thermal aging on board level drop reliability for Pb-free BGA packages , 2004, 2004 Proceedings. 54th Electronic Components and Technology Conference (IEEE Cat. No.04CH37546).