Parametric Studies of Effects of Solder Bump Pitch, Package Size, and Molding Compound and Substrate Thicknesses on Warpage of PBGA Packages

2014 ◽  
Vol 2014 (1) ◽  
pp. 000044-000049
Author(s):  
Sungbum Kang ◽  
I. Charles Ume

Plastic ball grid array (PBGA) is one of the most widely used types of chip packages in various electronic devices such as network servers, microcontrollers, and memory devices. As the demand for higher performance electronic devices grows, the I/O densities of PBGA packages are increasing while requiring superior reliability. Warpage induced during the reflow assembly process is one of the crucial factors affecting the thermo-mechanical reliability of PBGA packages; therefore, accurate warpage prediction is an important task for package design processes. In this study, the effects of four geometric factors (the solder bump pitch, package size, and molding compound and substrate thicknesses) of the PBGA package on its warpage are assessed by using parametric finite element analysis. The correlation between PBGA warpage and the four factors is studied using the regression method. These results are expected to provide design guidelines for in-house PBGA designers.

Computers ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 2 ◽  
Author(s):  
Miguel Abambres ◽  
Komal Rajana ◽  
Konstantinos Tsavdaridis ◽  
Tiago Ribeiro

Cellular beams are an attractive option for the steel construction industry due to their versatility in terms of strength, size, and weight. Further benefits are the integration of services thereby reducing ceiling-to-floor depth (thus, building’s height), which has a great economic impact. Moreover, the complex localized and global failures characterizing those members have led several scientists to focus their research on the development of more efficient design guidelines. This paper aims to propose an artificial neural network (ANN)-based formula to precisely compute the critical elastic buckling load of simply supported cellular beams under uniformly distributed vertical loads. The 3645-point dataset used in ANN design was obtained from an extensive parametric finite element analysis performed in ABAQUS. The independent variables adopted as ANN inputs are the following: beam’s length, opening diameter, web-post width, cross-section height, web thickness, flange width, flange thickness, and the distance between the last opening edge and the end support. The proposed model shows a strong potential as an effective design tool. The maximum and average relative errors among the 3645 data points were found to be 3.7% and 0.4%, respectively, whereas the average computing time per data point is smaller than a millisecond for any current personal computer.


2017 ◽  
Vol 84 (11) ◽  
Author(s):  
Yuhang Li ◽  
Jianpeng Zhang ◽  
Yufeng Xing ◽  
Jizhou Song

Epidermal electronic devices (EEDs) are very attractive in applications of monitoring human vital signs for diagnostic, therapeutic, or surgical functions due to their ability for integration with human skin. Thermomechanical analysis is critical for EEDs in these applications since excessive heating-induced temperature increase and stress may cause discomfort. An axisymmetric analytical thermomechanical model based on the transfer matrix method, accounting for the coupling between the Fourier heat conduction in the EED and the bio-heat transfer in human skin, the multilayer feature of human skin and the size effect of the heating component in EEDs, is established to study the thermomechanical behavior of the EED/skin system. The predictions of the temperature increase and principle stress from the analytical model agree well with those from finite element analysis (FEA). The influences of various geometric parameters and material properties of the substrate on the maximum principle stress are fully investigated to provide design guidelines for avoiding the adverse thermal effects. The thermal and mechanical comfort analyses are then performed based on the analytical model. These results establish the theoretical foundation for thermomechanical analysis of the EED/skin system.


2015 ◽  
Vol 2015 (DPC) ◽  
pp. 000639-000655
Author(s):  
Mingji Wang ◽  
Wei Li

Second level interconnect (SLI) or board level reliability (BLR) solder joint fatigue has been investigated extensively by OEM, ODM and OSAT. The influencing factors are well understood that package form factor (FF) and BGA pattern are primary factors. Modeling and testing correlate well in identifying failure location and predicting fatigue life. Previously bump level (FLI) is less touched due to large pitch and less fatigue reliability concerns. With the technology shift to more Chip Scale Package (CSP) FF and finer bump pitch, bump fatigue failure frequently occurs and meeting the reliability requirement become more challenging. However, even bump fatigue becomes more prominent, still not enough effort has been invested due to the modeling complexity when UF is present. As the first step towards developing bump fatigue life prediction, we carried out parametric finite element analysis (FEA) and investigated the factors from material, packaging design aspects that are often neglected in BLR. FEA study showed that with the presence of underfill, more factors than SLI/BLR influence the bump fatigue failure prediction. Key parameters that could affect failure location and life prediction are presented here.


2018 ◽  
Author(s):  
Miguel Abambres ◽  
Komal Rajana ◽  
Konstantinos Tsavdaridis ◽  
Tiago Ribeiro

Cellular beams are an attractive option for the steel construction industry due to their versatility in terms of strength, size, and weight. Further benefits are the integration of services thereby reducing ceiling-to-floor depth (thus, building’s height), which has a great economic impact. Moreover, the complex localised and global failures characterizing those members have led several scientists to focus their research on the development of more efficient design guidelines. This paper aims to propose an artificial neural network (ANN)-based formula to estimate the critical elastic buckling load of simply supported cellular beams under uniformly distributed vertical loads. The 3645-point dataset used in ANN design was obtained from an extensive parametric finite element analysis performed in ABAQUS. The independent variables adopted as ANN inputs are the following: beam’s length, opening diameter, web-post width, cross-section height, web thickness, flange width, flange thickness, and the distance between the last opening edge and the end support. The proposed model shows a strong potential as an effective design tool. The maximum and average relative errors among the 3645 data points were found to be 3.7% and 0.4%, respectively, whereas the average computing time per data point is smaller than a millisecond for any current personal computer.


Author(s):  
Luis A. Curiel ◽  
Andrew J. Komrowski ◽  
Daniel J.D. Sullivan

Abstract Acoustic Micro Imaging (AMI) is an established nondestructive technique for evaluation of electronic packages. Non-destructive evaluation of electronic packages is often a critical first step in the Failure Analysis (FA) process of semiconductor devices [1]. The molding compound to die surface interface of the Plastic Ball Grid Array (PBGA) and Plastic Quad Flat Pack (PQFP) packages is an important interface to acquire for the FA process. Occasionally, with these packages, the standard acoustic microscopy technique fails to identify defects at the molding compound to die surface interface. The hard to identify defects are found at the edge of the die next to the bond pads or under the bonds wires. This paper will present a technique, Backside Acoustic Micro Imaging (BAMI) analysis, which can better resolve the molding compound to die surface interface at the die edge by sending the acoustic signal through the backside of the PBGA and PQFP packages.


2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Muhammad Bilal Adeel ◽  
Muhammad Asad Jan ◽  
Muhammad Aaqib ◽  
Duhee Park

The behavior of laterally loaded pile groups is usually accessed by beam-on-nonlinear-Winkler-foundation (BNWF) approach employing various forms of empirically derived p-y curves and p-multipliers. Averaged p-multiplier for a particular pile group is termed as the group effect parameter. In practice, the p-y curve presented by the American Petroleum Institute (API) is most often utilized for piles in granular soils, although its shortcomings are recognized. In this study, we performed 3D finite element analysis to develop p-multipliers and group effect parameters for 3 × 3 to 5 × 5 vertically squared pile groups. The effect of the ratio of spacing to pile diameter (S/D), number of group piles, varying friction angle (φ), and pile fixity conditions on p-multipliers and group effect parameters are evaluated and quantified. Based on the simulation outcomes, a new functional form to calculate p-multipliers is proposed for pile groups. Extensive comparisons with the experimental measurements reveal that the calculated p-multipliers and group effect parameters are within the recorded range. Comparisons with two design guidelines which do not account for the pile fixity condition demonstrate that they overestimate the p-multipliers for fixed-head condition.


2010 ◽  
Vol 145 ◽  
pp. 567-572
Author(s):  
Hua Ding ◽  
Zhao Jian Yang ◽  
Xue Wen Wang ◽  
Zhi Yong Ding

Based on the concept of parametric design, this paper realizes the parametric modeling and parametric finite element analysis by utilizing UG/OPEN secondary development tool and APDL module of ANSYS software respectively. This paper also achieves data sharing of CAD/CAE through compiling interface program between UG6.0 and ANSYS10.0. In addition, the remote design and analysis platform has been built by using ASP.NET technology, component technology, and database technology. We take piston-piston rod part of coal mining machine’s cutting unit as an example to verify the system. Meanwhile, it proves system can effectively shorten design and analysis cycle time, and reduce workload of designer. Therefore, this software has potential application value in engineering.


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