A Constriction Resistance Model in Thermal Analysis of Solder Ball Joints in Ball Grid Array Packages

1999 ◽  
Author(s):  
T. M. Ying ◽  
K. C. Toh
Keyword(s):  
Thermal Analysis ◽  
Solder Joint ◽  
Solder Ball ◽  
Heat Dissipation ◽  
Ball Grid Array ◽  
Internal Resistance ◽  
Ball Joint ◽  
Constriction Resistance ◽  
Resistance Model ◽  
Ball Joints

Abstract The constriction resistance model is employed for the thermal analysis at the solder ball joint of a Ball Grid Array (BGA) package. The behavior of heat dissipation in solder joint is also analyst through Finite Element Modeling (FEM) and compared with the analytical model. The principle of constriction and spreading resistances is analyzed in detail because of the geometrical complexity encountered in BGA solder joints. The total resistance across the solder joint includes the internal resistance and external resistance. The internal resistance, which is the main focus of the analysis, consists of material resistance and constriction resistance. It is a function of material conductivity, thermal boundary conditions and geometric parameters. FEM solutions are in good agreement with analytical results of thermal resistance for single solder ball joint and multiple solder ball joints. The analytical resistance provides an accurate prediction on the temperature drop across the array of solder balls and hence the overall performance of the BGA packages. The pitch size is the main parameter in the investigation to study the heat dissipation of solder ball joints.

scholarly journals Deformation Evaluation of Solder Ball Joints by Electromotive Force

2008 ◽  
Vol 13-14 ◽  
pp. 233-238
Author(s):  
T. Kumazawa ◽  
K. Kaminishi
Keyword(s):  
Solder Joint ◽  
Electromotive Force ◽  
Solder Ball ◽  
Solder Joints ◽  
Shear Fracture ◽  
Testing Machine ◽  
Copper Layer ◽  
Deformation Test ◽  
Ball Joints ◽  
Deformation Measurements

Deformation measurements with a thermocouple were applied in a deformation test of solder joints. The thermocouple is effectively combined with a conventional testing machine. The lead–solder and non–lead solder joints were pulled and sheared. The load-displacement and electromotive force (Emf)–displacement curves can be continuously derived from the signals of a load cell and the thermocouple. The Emfs in tension were compared with that in shear. The maximum Emf value in tension was larger than the emf value in shear, which meant in weakness of the solder joint in shear. Fracture occurred at the interface between the copper layer pad and solder, and the obtained Emf is closely related to fracture at the interface. The maximum Emf value in the non-lead solder was smaller than the Emf value in the lead–solder.

Simplified Three-Dimensional Thermomechanical Applications of Ball Grid Array Package

2011 ◽  
Vol 403-408 ◽  
pp. 256-265
Author(s):  
Jia Mao ◽  
Wei Hua Zhang
Keyword(s):  
Fatigue Life ◽  
Solder Ball ◽  
Three Dimensional ◽  
Reference Value ◽  
Ball Grid Array ◽  
Deformation Energy ◽  
Design Parameters ◽  
Ball Joint ◽  
Detailed Model ◽  
Improved Model

Three dimensional finite element models were created utilizing APDL (ANSYS Parametric Design Language) for typical multi-chip BGAP (Ball Grid Array Packages) with different sizes to analyze the structure stress and strain when loading steady thermal loads upon them. Subsequently an improved modeling approach including equivalent beam and critical solder ball joint for simplification was studied and introduced. The Darveaux method based on plastic deformation energy accumulation for predicting fatigue life of solder ball joint under thermal cyclic loading was applied to the improved model for calculation, and effects of main design parameters upon fatigue life were studied accordingly. The numerical results reflected the stress distribution and varying traits of the package, compare of results between improved model and detailed model indicates that the simplified modeling method is quite effective and available for different types of analysis. Methods and results of this paper are of certain reference value for the design and optimization for similar kind of packages.

The micro-impact fracture behavior of lead-free solder ball joints

2008 ◽  
Vol 23 (4) ◽  
pp. 1057-1063 ◽  
Author(s):  
Y.L. Huang ◽  
K.L. Lin ◽  
D.S. Liu
Keyword(s):  
Solder Joint ◽  
Fracture Energy ◽  
Fracture Behavior ◽  
Solder Ball ◽  
Impact Fracture ◽  
Lead Free ◽  
Lead Free Solder ◽  
Impact Fracture Behavior ◽  
Free Solder ◽  
Ball Joints

The present study investigated the micro-impact fracture behavior of various lead-free solder joints, including Sn–1Ag–0.1Cu–0.02Ni–0.05In, Sn–1.2Ag–0.5Cu–0.05Ni, and Sn–1Ag–0.5Cu. The fracture that occurs within the solder joint corresponds to a higher impact fracture energy (1.35 mJ), while the fracture at the interface between the solder joint and intermetallic compound acquires a smaller impact energy (0.82 mJ). Two types of fracture mechanisms were proposed based on observations of the fracture morphology and the impact curve for the solder ball joints. The longer deflection distance, referring to better elongation, exists for the mechanism corresponding to the higher fracture energy.

Device architecture optimization of solder ball joints fatigue lifetime under random vibration frequencies

2020 ◽  
Vol 33 (1) ◽  
pp. 1-7
Author(s):  
Yang Gao ◽  
Fuwei Wang ◽  
Shaohu Ding ◽  
Bin Yang ◽  
Lin Liu ◽  
...  
Keyword(s):  
Random Vibration ◽  
Design Methodology ◽  
Solder Ball ◽  
Ball Grid Array ◽  
Fatigue Lifetime ◽  
Content Type ◽  
Device Architecture ◽  
Ball Joints ◽  
Architecture Optimization ◽  
Circuit Configuration

Purpose This study aims to investigate the vibration effects on ball grid array lifetime. Design/methodology/approach Several finite element method simulations and experiments were performed. Findings An optimized circuit configuration was found. Originality/value The originality of paper is confirmed by authors.

The Effect of Ball Pad Metallurgy and Ball Composition on Solder Ball Integrity of Plastic Ball Grid Array Packages

1998 ◽  
Author(s):  
C.H. Zhong ◽  
Sung Yi
Keyword(s):  
Failure Mode ◽  
Barrier Layer ◽  
Shear Force ◽  
Solder Ball ◽  
Ball Grid Array ◽  
Reliability Test ◽  
Shear Forces ◽  
Ball Shear ◽  
Plastic Ball ◽  
Plastic Ball Grid Array

Abstract Ball shear forces of plastic ball grid array (PBGA) packages are found to decrease after reliability test. Packages with different ball pad metallurgy form different intermetallic compounds (IMC) thus ball shear forces and failure modes are different. The characteristic and dynamic process of IMC formed are decided by ball pad metallurgy which includes Ni barrier layer and Au layer thickness. Solder ball composition also affects IMC formation dynamic process. There is basically no difference in ball shear force and failure mode for packages with different under ball pad metallurgy before reliability test. However shear force decreased and failure mode changed after reliability test, especially when packages exposed to high temperature. Major difference in ball shear force and failure mode was found for ball pad metallurgy of Ni barrier layer including Ni-P, pure Ni and Ni-Co. Solder ball composition was found to affect the IMC formation rate.

No more rattling: biomechanical evaluation of a hexapod ring fixator free of play

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Markus Greinwald ◽  
Emily K. Bliven ◽  
Alex Trompeter ◽  
Peter Augat
Keyword(s):  
Mechanical Performance ◽  
Steel Frame ◽  
Ball Joint ◽  
Universal Joint ◽  
Ring Fixator ◽  
Low Weight ◽  
Biomechanical Evaluation ◽  
Axial Fracture ◽  
Ball Joints ◽  
Universal Joints

Abstract Hexapod-ring-fixators have a characteristic rattling sound during load changes due to play in the hexapod struts. This play is perceived as unpleasant by patients and can lead to frame instability. Using slotted-ball-instead of universal-joints for the ring-strut connection could potentially resolve this problem. The purpose of the study was to clarify if the use of slotted-ball-joints reduces play and also fracture gap movement. A hexapod-fixator with slotted-ball-joints and aluminum struts (Ball-Al) was compared to universal-joint-fixators with either aluminum (Uni Al) or steel struts (Uni Steel). Six fixator frames each were loaded in tension, compression, torsion, bending and shear and mechanical performance was analyzed in terms of movement, stiffness and play. The slotted-ball-joint fixator was the only system without measurable axial play (<0.01 mm) compared to Uni-Al (1.2 ± 0.1) mm and Uni-Steel (0.6 ± 0.2) mm (p≤0.001). In both shear directions the Uni-Al had the largest play (p≤0.014). The resulting axial fracture gap movements were similar for the two aluminum frames and up to 25% smaller for the steel frame, mainly due to the highest stiffness found for the Uni-Steel in all loading scenarios (p≤0.036). However, the Uni-Steel construct was also up to 29% (450 g) heavier and had fewer usable mounting holes. In conclusion, the slotted-ball-joints of the Ball-Al fixator reduced play and minimized shear movement in the fracture while maintaining low weight of the construct. The heavier and stiffer Uni-Steel fixator compensates for existing play with a higher overall stiffness.

scholarly journals Thermal Analysis of Cold Plate with Different Configurations for Thermal Management of a Lithium-Ion Battery

Batteries ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 17
Author(s):  
Seyed Saeed Madani ◽  
Erik Schaltz ◽  
Søren Knudsen Kær
Keyword(s):  
Thermal Analysis ◽  
Temperature Distribution ◽  
Lithium Ion Battery ◽  
Thermal Management ◽  
Electric Vehicles ◽  
Heat Dissipation ◽  
Lithium Ion ◽  
Cold Plate ◽  
Liquid Cooling ◽  
Cooling Design

Thermal analysis and thermal management of lithium-ion batteries for utilization in electric vehicles is vital. In order to investigate the thermal behavior of a lithium-ion battery, a liquid cooling design is demonstrated in this research. The influence of cooling direction and conduit distribution on the thermal performance of the lithium-ion battery is analyzed. The outcomes exhibit that the appropriate flow rate for heat dissipation is dependent on different configurations for cold plate. The acceptable heat dissipation condition could be acquired by adding more cooling conduits. Moreover, it was distinguished that satisfactory cooling direction could efficiently enhance the homogeneity of temperature distribution of the lithium-ion battery.

Thermal Analysis of Ball Grid Array Non-Volatile Memory Express Solid-State Drive in Vacuum

2018 ◽  
Vol 39 (12) ◽  
pp. 1908-1911
Author(s):  
Eung Chang Lee ◽  
Jinsung Rho ◽  
Heeyoub Kang ◽  
Bong Jae Lee
Keyword(s):  
Thermal Analysis ◽  
Solid State ◽  
Ball Grid Array ◽  
Solid State Drive ◽  
Non Volatile Memory ◽  
Volatile Memory

Effect of Thickness of Pd Plating Layer on Shear Strength of Lead-Free Solder Ball Joint With Electroless Ni/Pd/Au Plated Electrode

2011 ◽  
Author(s):  
Takahiro Kano ◽  
Ikuo Shohji ◽  
Tetsuyuki Tsuchida ◽  
Toshikazu Ookubo
Keyword(s):  
Reaction Layer ◽  
Shear Force ◽  
Solder Ball ◽  
Lead Free ◽  
Joint Interface ◽  
Lead Free Solder ◽  
Solder Balls ◽  
Free Solder ◽  
Ball Joints ◽  
Electroless Ni

An electroless Ni/Pd/Au plated electrode is expected to be used as an electrode material for lead-free solder to improve joint reliability. The aim of this study is to investigate the effect of the thickness of the Pd layer on joint properties of the lead-free solder joint with the electroless Ni/Pd/Au plated electrode. Solder ball joints were fabricated with Sn-3Ag-0.5Cu (mass%) lead-free solder balls and electroless Ni/Pd/Au and Ni/Au plated electrodes. Ball shear force and microstructure of the joint were investigated. The (Cu,Ni)6Sn5 reaction layer formed in the joint interface in all specimens. The thickness of the reaction layer decreased with increasing the thickness of the Pd layer. In the joint with a Pd layer 0.36 μm thick, the remained Pd layer was observed in the joint interface. In the joint, impact shear force decreased compared with that of the joint without the remained Pd layer. On the contrary, when the thickness of the Pd layer was less than 0.36 μm, the Pd layer was not remained in the joint interface and impact shear force improved. Impact shear force of the joint with the electroless Ni/Pd/Au plated electrode was higher than that with the electroless Ni/Au one.

Ball Grid Array (BGA) Solder Joint Intermittency Detection: SJ BIST

2008 ◽  
Author(s):  
James P. Hofmeister ◽  
Pradeep Lall ◽  
Dhananjay Panchagade ◽  
Norman N. Roth ◽  
Terry A. Tracy ◽  
...  
Keyword(s):  
Solder Joint ◽  
Ball Grid Array
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