Reliability enhancement of electronic packages by design of optimal parameters

2004 ◽  
Vol 44 (7) ◽  
pp. 1157-1163 ◽  
Author(s):  
Ashish Batra ◽  
Pradeep Ramachandran ◽  
Poornima Sathyanarayanan ◽  
Susan Lu ◽  
Hari Srihari

The article is devoted to the actual problem of assigning optimal parameters for connecting steel plates on cover plates with angular welds that are widely used in construction practice. The article presents the results of a comprehensive study of operation of a welded assembly of the plates connection on cover plates. An algorithm is proposed for determining the optimal parameters of a welded joint with fillet welds on the cover plates, which makes it possible to obtain a strength balanced connection. The results of full-scale tensile tests of models were presented. These results confirmed the correctness of the assumed design assumptions, and made it possible to obtain a form of destruction, not characteristic and not described in the normative literature, expressed by cutting the main elements along the length of the overlap in the joint. The possibility of such a form of destruction was confirmed by the results of numerical research in a nonlinear formulation. The optimal parameters of the nodal welded joint determined by engineering calculation are confirmed by experimental studies, as well as by the results of numerical experiments on models of calculation schemes, taking into account the physical nonlinearity of the material operation. The obtained dependence for determining the bearing capacity of the joint by the cut-off mechanism and the expression for limiting the overlap length of the cover plates will make it possible to predict the nature of the fracture and design equally strong joints.


Author(s):  
Wenhua ZHANG ◽  
Shidong ZHANG ◽  
Yong WANG ◽  
Jianpeng WANG

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.


Author(s):  
Andrew J. Komrowski ◽  
Luis A. Curiel ◽  
Daniel J. D. Sullivan ◽  
Quang Nguyen ◽  
Lisa Logan-Willams

Abstract The acquisition of reliable Acoustic Micro Images (AMI) are an essential non-destructive step in the Failure Analysis (FA) of electronic packages. Advanced packaging and new IC materials present challenges to the collection of reliable AMI signals. The AMI is complicated due to new technologies that utilize an increasing number of interfaces in ICs and packages. We present two case studies in which it is necessary to decipher the acoustic echoes from the signals generated by the interface of interest in order to acquire trustworthy information about the IC package.


Author(s):  
Deepak Goyal

Abstract Next generation assembly/package development challenges are primarily increased interconnect complexity and density with ever shorter development time. The results of this trend present some distinct challenges for the analytical tools/techniques to support this technical roadmap. The key challenge in the analytical tools/techniques is the development of non-destructive imaging for improved time to information. This paper will present the key drivers for the non-destructive imaging, results of literature search and evaluation of key analytical techniques currently available. Based on these studies requirements of a 3D imaging capability will be discussed. Critical breakthroughs required for development of such a capability are also summarized.


2019 ◽  
Vol 1 (3) ◽  
pp. 1-10
Author(s):  
Mikhail M. Konstantinov ◽  
Ivan N. Glushkov ◽  
Sergey S. Pashinin ◽  
Igor I. Ognev ◽  
Tatyana V. Bedych

In this paper we consider the structural and technological process of the combine used in the process of separate harvesting of grain crops, as well as a number of its parameters. Among the main units of the combine, we allocate a conveyor and devices for removing beveled stems from under the wheels of the vehicle. The principle of operation of the conveyor at different phases of the Reaper and especially the removal of cut stems from under the wheels of the vehicle during operation of the Reaper. The results of theoretical studies on the establishment of the optimal design of the parameters of the belt conveyor are presented, the ranges of their optimal values are considered and determined. Studies on the establishment of optimal parameters of the screw divider in the Reaper, which is the main component of the device for removal of beveled stems, are presented. Taking into account the optimal design and mode of operation of the screw divider, the correct work is provided to remove the cut stems from under the wheels of the harvester.


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