Thermomechanical Durability of High I/O BGA Packages

2002 ◽  
Vol 124 (3) ◽  
pp. 266-270 ◽  
Author(s):  
P. Davuluri ◽  
S. Shetty ◽  
A. Dasgupta ◽  
S. Young
Keyword(s):  
Solder Joint ◽  
Ball Grid Array ◽  
Element Model ◽  
Hybrid Technique ◽  
Failure Data ◽  
Bga Packages ◽  
Analysis Technique ◽  
Bga Package ◽  
Parametric Studies ◽  
Failure Predictions

Efficient modeling strategies are developed to study thermomechanical durability of high I/O Ball Grid Array (BGA) packages, in order to facilitate virtual qualification and accelerated testing of component designs. A viscoplastic stress analysis technique is developed where the critical solder joint(s) (joint(s) where failure first occurs) are modeled in detail with a multi-domain Rayleigh-Ritz (MDRR) methodology while the load-sharing offered by noncritical joints is modeled with a simplified compact model. This hybrid technique is used to study the behavior of solder interconnects in selected Ball Grid Array (BGA) package under thermal cycling environments. Parametric studies are conducted to determine the optimal scheme for allocating a critical number of solder joints to the MDRR model, and the remaining non-critical joints to the compact models. Damage calculations are made with the Energy Partitioning Solder Durability model and cycles-to-failure predictions are compared with both finite element model predictions as well as experimental failure data provided by CALCE EPSC sponsors. Parametric studies on change in solder joint durability with interconnect volume are also discussed in this paper.

Thermomechanical Durability of High I/O BGA Packages

2000 ◽  
Author(s):  
Pavan Davuluri ◽  
Abhijit Dasgupta ◽  
Steven Young
Keyword(s):  
Solder Joint ◽  
Ball Grid Array ◽  
Element Model ◽  
Hybrid Technique ◽  
Failure Data ◽  
Bga Packages ◽  
Analysis Technique ◽  
Bga Package ◽  
Parametric Studies ◽  
Failure Predictions

Abstract Efficient modeling strategies are developed to study thermomechanical durability of high I/O Ball Grid Array (BGA) packages, in order to facilitate virtual qualification and accelerated testing of component designs. A viscoplastic stress analysis technique is developed where the critical solder joint(s) (joint(s) at which failure first occurs) are modeled in detail with a multi-domain Rayleigh-Ritz (MDRR) methodology (Ling and Dasgupta, 1996; Ling and Dasgupta 1997; Ling 1997; and Rassian and Lee, 1998) while the load-sharing offered by non-critical joints is modeled with a simplified compact model. This hybrid technique is used to study the behavior of solder interconnects in selected Ball Grid Array (BGA) package under thermal cycling environments. Parametric studies are conducted to determine the optimal scheme for allocating a critical number of solder joints to the MDRR model, and the remaining non-critical joints to the compact models. Damage calculations are made with the Energy Partitioning Solder Durability model (Dasgupta et al., 1992) and cycles-to-failure predictions are compared with both finite element model predictions as well as experimental failure data provided by CALCE EPSC sponsors. Parametric studies on change in solder joint durability with interconnect volume are also discussed in this paper.

Emerging Flux Challenges for BGA Packages

2016 ◽  
Vol 2016 (DPC) ◽  
pp. 001359-001390
Author(s):  
Maria Durham ◽  
Andy Mackie ◽  
Jason Chou
Keyword(s):  
Solder Joint ◽  
Failure Modes ◽  
Value Added ◽  
Ball Grid Array ◽  
Deposition Process ◽  
Testing Methods ◽  
Bga Packages ◽  
Bga Package ◽  
One Step ◽  
Process Cost

The formation of a Ball Grid Array (BGA) solder joint is critical for a BGA package where typically a flux deposition process is used. Reflowing solder spheres to solderable pads on the bottom of substrates in standard BGA, FCBGA, CSP, and similar packages is considered to be a trivial step: a specialized BGA flux is usually pin-transferred onto the pads, followed by balldrop onto the substrate. However, with the increasing complexity and number of assembly processes taken prior to this final step, the formation of a reliable final joint is far from certain. In order to eliminate variability, many OSATs and ODMs use the so-called “two step” (double fluxing) approach, which is comprised of the non-value-added extra processes of prefluxing, reflowing, cleaning, and drying substrates immediately prior to the final flux-based ball-attach process. This paper details the sequence of processes seen in typical FCBGA assembly, and examines the effects of each set of prior processes on the solderability of the final pad. The introduction of a “one-step” pin-transfer ball-attach flux is shown to be a means of reducing both process cost and time, and also reducing the risk of increased warpage in the finished package. The paper also investigates the solderable surface and metallurgy of the substrate pad. The variety of new and emerging failure modes for the BGA process as well as the different testing methods for the materials will also be discussed.

Development of Reliability and Moldability on Fine Pitch Ball Grid Array by Optimizing Materials

2000 ◽  
Vol 123 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Takashi Aihara ◽  
Shingo Ito ◽  
Hideaki Sasajima ◽  
Ken Oota
Keyword(s):  
Ball Grid Array ◽  
The Other ◽  
Molding Compounds ◽  
Other Hand ◽  
Die Attach ◽  
Bga Packages ◽  
Fine Pitch ◽  
The World ◽  
Bga Package ◽  
Materials Used

The market for BGA packages is expanding all over the world, owing to the ease of its mounting onto the PC boards. On the other hand, BGA packages possess certain shortcomings compared to QFPs. Anti-solder crack performance on Fine Pitch BGA (=FPBGA) and warpage on Mold Array Package-BGA(=MAP-BGA) are significant disadvantages. To improve the performance of BGA packages, we studied various combinations of materials used for BGA package including molding compounds, die attach pastes, and substrates.

Thermal analysis and optimization for a ball grid array package

2005 ◽  
Vol 219 (4) ◽  
pp. 381-393 ◽  
Author(s):  
C-I Ho ◽  
T-C Hung ◽  
C-I Hung
Keyword(s):  
Thermal Resistance ◽  
Heat Dissipation ◽  
Ball Grid Array ◽  
Optimization Method ◽  
Heat Transfer Analysis ◽  
Bga Packages ◽  
Solder Balls ◽  
Bga Package ◽  
Computational Fluid Dynamics Cfd ◽  
Artificial Neural Network Ann

In this study, a computational fluid dynamics (CFD) approach is employed for heat transfer analysis of a ball grid array (BGA) package that is widely used in the modern electronics industry. Owing to the complicated geometric configuration of the BGA package, the submodel approach is used to investigate in detail the temperature distributions of thermal vias and solder balls. The effective thermal resistance of a BGA package has been successfully obtained from numerical simulations. An artificial neural network (ANN) is trained to establish the relationship between the geometry input and the thermal resistance output. The well-trained network is then coupled with the complex optimization method to search for the optimum design of the BGA package to achieve the lowest thermal resistance. The results of this study provide the electronic packaging industry with a reliable and rapid method for heat dissipation design of BGA packages.

Direct Measurement of Silicon Strain in a Fine Pitch Flip Chip BGA Package

2017 ◽  
Vol 2017 (1) ◽  
pp. 000176-000181
Author(s):  
Nathan Whitchurch ◽  
Glenn Rinne ◽  
Wei Lin ◽  
Devarajan Balaraman
Keyword(s):  
Finite Element ◽  
Flip Chip ◽  
Geometric Model ◽  
Ball Grid Array ◽  
Element Model ◽  
Strain Component ◽  
Front Side ◽  
Fine Pitch ◽  
Bga Package ◽  
Measured Displacement

Abstract A method for directly measuring the silicon strain in a flip chip ball grid array (FCBGA) package is disclosed. The method uses anisotropically etched holes in the die backside to reveal fiducial crosses on the front side of the die. A geometric model is proposed that allows extraction of the strain component of the measured displacement. A finite element model is described which correctly predicts the sign and magnitude of the strain.

Effects of Ceramic Ball-Grid-Array Package’s Manufacturing Variations on Solder Joint Reliability

1994 ◽  
Vol 116 (4) ◽  
pp. 242-248 ◽  
Author(s):  
Teh-Hua Ju ◽  
Wei Lin ◽  
Y. C. Lee ◽  
Jay J. Liu
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Solder Joints ◽  
Ball Grid Array ◽  
Printed Wiring Board ◽  
Ceramic Ball ◽  
Solder Volume ◽  
Bga Package ◽  
Reliability Of Solder Joints ◽  
Wiring Board

The effects of manufacturing variations on the reliability of solder joints between a ceramic ball grid array (BGA) package and a printed wiring board (PWB) are investigated. Two cases are studied, namely, with and without spacers between the BGA package and the PWB to maintain the solder joint height. Manufacturing variations considered include changes in solder volume, joint height, and pad size. To evaluate the effect of manufacturing variations on reliability, every possible solder joint profile is first derived. The maximum strain is calculated next. Finally, the fatigue life is predicted. The calculations show that these manufacturing variations change the joint profile, and subsequently affect the fatigue life. Since the package is heavy, the use of spacers is necessary to control the solder joint height for reliable connections, and to maintain a large gap for cleaning. The solder joints formed with the use of spacers, may have convex, cylindrical or concave profiles. The concave solder joints are preferred, since they have long fatigue lives and are less sensitive to the manufacturing variations. For the convex solder joints, their fatigue lives are strongly affected by the joint height variation caused by package warpage and by the combined effects of solder volume and pad size.

Wear Modeling of Nanometer Thick Protective Coatings

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Jungkyu Lee ◽  
Youfeng Zhang ◽  
Robert M. Crone ◽  
Narayanan Ramakrishnan ◽  
Andreas A. Polycarpou
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Protective Coatings ◽  
Element Model ◽  
Disk Surface ◽  
Magnetic Storage ◽  
Theoretical Frameworks ◽  
Storage Devices ◽  
Parametric Studies ◽  
Magnetic Storage Devices

Use of nanometer thin films has received significant attention in recent years because of their advantages in controlling friction and wear. There have been significant advances in applications such as magnetic storage devices, and there is a need to explore new materials and develop experimental and theoretical frameworks to better understand nanometer thick coating systems, especially wear characteristics. In this work, a finite element model is developed to simulate the sliding wear between the protruded pole tip in a recording head (modeled as submicrometer radius cylinder) and a rigid asperity on the disk surface. Wear is defined as plastically deformed asperity and material yielding. Parametric studies reveal the effect of the cylindrical asperity geometry, material properties, and contact severity on wear. An Archard-type wear model is proposed, where the wear coefficients are directly obtained through curve fitting of the finite element model, without the use of an empirical coefficient. Limitations of such a model are also discussed.

Cooling of Thermal Enhanced BGA Package Using Foam Metal Heat Sinks

2000 ◽  
Author(s):  
Jenn-Jiang Hwang ◽  
Chung-Hsing Chao
Keyword(s):  
Heat Sink ◽  
Power Dissipation ◽  
Thermal Characterization ◽  
Junction Temperature ◽  
Pin Fin ◽  
Bga Packages ◽  
Plastic Ball ◽  
Bga Package ◽  
Foam Metal ◽  
Forced Air

Abstract This study reported thermal performance of a thermally enhanced plastic ball grid array (PBGA), namely T2-BGA™ which incorporates a heat slug in package, with a foam-metal heat sink on the top of this package. Experimental measurement of junction-to-ambient thermal resistance is performed in accordance with the SEMI standards of G38-0996 and G42-0996 for thermal characterization of BGA packages. Allowable power dissipation is subject to the constraint of junction temperature (Tj) at 95°C and ambient temperature (Ta) in chassis at 35 °C under free and forced air (0 ∼ 3 m/s) conditions. Based on this constraint, allowable power dissipation of a regular PBGA with a commercial pin fin heat sink under free and 3 m/s forced air is 5.45 W and 9.17 W compared with those of T2-BGA with a foam heat sink of 6.80 W and 19.6 W respectively. This results show that T2-BGA™ with a foam heat sink offers enormous potential to high power package applications.

Sign in / Sign up

Export Citation Format

Share Document