scholarly journals Simulation Research on Sparse Reconstruction for Defect Signals of Flip Chip Based on High-Frequency Ultrasound

2020 ◽  
Vol 10 (4) ◽  
pp. 1292
Author(s):  
Xiaonan Yu ◽  
Hairun Huang ◽  
Wanlong Xie ◽  
Jiefei Gu ◽  
Ke Li ◽  
...  
Keyword(s):  
High Frequency ◽  
Flip Chip ◽  
Acoustic Energy ◽  
Acoustic Microscopy ◽  
Propagation Path ◽  
Sparse Reconstruction ◽  
High Frequency Ultrasound ◽  
Microscopy Imaging ◽  
Chip Technology ◽  
Solder Balls

Flip chip technology has been widely used in various fields. As the density of the solder balls in flip chip technology is increasing, the pitch among solder balls is narrowing, and the size effect is more significant. Therefore, the micro defects of the solder balls are more difficult to detect. In order to ensure the reliability of the flip chip, it is very important to detect and evaluate the micro defects of solder balls. High-frequency ultrasonic testing technology is an effective micro-defect detection method. In this paper, the interaction mechanism between high-frequency ultrasonic pulse and micro defects is analyzed by finite element simulation. A transient simulation model for the whole process of ultrasonic scanning of micro defects is established to simulate scanning in acoustic microscopy imaging. The acoustic propagation path map is obtained for analyzing acoustic energy transmission during detection, and the edge blurring effect in micro-defect imaging detection is clarified. The processing method of the time-domain signal and cross-section image signal of micro defects based on sparse reconstruction is studied, which can effectively improve the accuracy of detection and the signal-to-noise ratio.

Failure Analysis of Flip-Chip Interconnections Through Acoustic Microscopy

1996 ◽  
Author(s):  
O. Diaz de Leon ◽  
M. Nassirian ◽  
C. Todd ◽  
R. Chowdhury
Keyword(s):  
Failure Analysis ◽  
Large Scale ◽  
Flip Chip ◽  
Ultrasonic Waves ◽  
Acoustic Microscopy ◽  
Acoustic Microscope ◽  
Chip Technology ◽  
Ball Joints ◽  
Non Destructive ◽  
Scanning Acoustic Microscope

Abstract Integration of circuits on semiconductor devices with resulting increase in pin counts is driving the need for improvements in packaging for functionality and reliability. One solution to this demand is the Flip- Chip concept in Ultra Large Scale Integration (ULSI) applications [1]. The flip-chip technology is based on the direct attach principle of die to substrate interconnection.. The absence of bondwires clearly enables packages to become more slim and compact, and also provides higher pin counts and higher-speeds [2]. However, due to its construction, with inherent hidden structures the Flip-Chip technology presents a challenge for non-destructive Failure Analysis (F/A). The scanning acoustic microscope (SAM) has recently emerged as a valuable evaluation tool for this purpose [3]. C-mode scanning acoustic microscope (C-SAM), has the ability to demonstrate non-destructive package analysis while imaging the internal features of this package. Ultrasonic waves are very sensitive, particularly when they encounter density variations at surfaces, e.g. variations such as voids or delaminations similar to air gaps. These two anomalies are common to flip-chips. The primary issue with this package technology is the non-uniformity of the die attach through solder ball joints and epoxy underfill. The ball joints also present defects as open contacts, voids or cracks. In our acoustic microscopy study packages with known defects are considered. It includes C-SCAN analysis giving top views at a particular package interface and a B-SCAN analysis that provides cross-sectional views at a desired point of interest. The cross-section analysis capability gives confidence to the failure analyst in obtaining information from a failing area without physically sectioning the sample and destroying its electrical integrity. Our results presented here prove that appropriate selection of acoustic scanning modes and frequency parameters leads to good reliable correlation between the physical defects in the devices and the information given by the acoustic microscope.

Impact of Reprocessing Technique on First Level Interconnects of Pb-Free to SnPb Reballed Area Array Flip Chip Devices

2014 ◽  
Vol 2014 (1) ◽  
pp. 000112-000116
Author(s):  
Joelle Arnold ◽  
Steph Gulbrandsen ◽  
Nathan Blattau
Keyword(s):  
Computer Tomography ◽  
Damage Accumulation ◽  
Flip Chip ◽  
Ball Grid Array ◽  
Acoustic Microscopy ◽  
Eutectic Solder ◽  
X Ray ◽  
Area Array ◽  
Solder Balls ◽  
Commercial Off The Shelf

The risk of damage caused by reballing SnPb eutectic solder balls onto a commercial off-the-shelf (COTS) active flip chip with a ball grid array (BGA) of SAC305 was studied. The effects of reballing performed by five different reballers were examined and compared. The active flip chip device selected included manufacturer specified resistance between eight (8) differential port pairs. The path resistance between these pins following reballing, as compared to an unreballed device, was used to assess damage accumulation in the package. 2-dimensional x-ray microscopy, acoustic microscopy, and x-ray computer tomography were also used to characterize the effects of reballing. These studies indicated that no measureable damage was incurred by the reballing process, implying that reballed devices should function as well as non-reballed devices in the same application.

Development of 3D System-in-Package with TSV Technology

2014 ◽  
Vol 2014 (1) ◽  
pp. 000612-000617 ◽  
Author(s):  
Shota Miki ◽  
Takaharu Yamano ◽  
Sumihiro Ichikawa ◽  
Masaki Sanada ◽  
Masato Tanaka
Keyword(s):  
High Performance ◽  
Flip Chip ◽  
Organic Substrate ◽  
Back Side ◽  
Final Thickness ◽  
Chip Technology ◽  
Type Semiconductor ◽  
Interconnect Reliability ◽  
Solder Balls ◽  
Carrier Wafer

In recent years, products such as smart phones, tablets, and wearable devices, are becoming miniaturized and high performance. 3D-type semiconductor structures are advancing as the demand for high-density assembly increases. We studied a fabrication process using a SoC die and a memory die for 3D-SiP (System in Package) with TSV technology. Our fabrication is comprised of two processes. One is called MEOL (Middle End of Line) for exposing and completing the TSV's in the SoC die, and the other is assembling the SoC and memory dice in a 3D stack. The TSV completion in MEOL was achieved by SoC wafer back-side processing. Because its final thickness will be a thin 50μm (typical), the SoC wafer (300 mm diameter) is temporarily attached face-down onto a carrier-wafer. Careful back-side grinding reveals the “blind vias” and fully opens them into TSV's. A passivation layer is then grown on the back of the wafer. With planarization techniques, the via metal is accessed and TSV pads are built by electro-less plating without photolithography. After the carrier-wafer is de-bonded, the thin wafer is sawed into dice. For assembling the 3D die stack, flip-chip technology by thermo-compression bonding was the method chosen. First, the SoC die with copper pillar bumps is assembled to the conventional organic substrate. Next the micro-bumps on the memory die are bonded to the TSV pads of the SoC die. Finally, the finished assembly is encapsulated and solder balls (BGA) are attached. The 3D-SiP has passed both package-level reliability and board-level reliability testing. These results show we achieved fabricating a 3D-SiP with high interconnect reliability.

Reliability Prediction of Area Array Solder Joints

2003 ◽  
Vol 125 (4) ◽  
pp. 562-568 ◽  
Author(s):  
Rainer Dudek ◽  
Ralf Do¨ring ◽  
Bernd Michel
Keyword(s):  
Geometric Modeling ◽  
Flip Chip ◽  
Failure Criteria ◽  
Temperature Fields ◽  
The Finite Element Method ◽  
Chip Technology ◽  
Array Technology ◽  
Chip Scale Package ◽  
Solder Balls

Packages for high pin counts using the ball grid array technology or its miniaturized version, the chip scale package, inherently require reliability concepts as an integral part of their development. This is especially true for the latter packages, if they are combined with the flip chip technology. Accordingly, thermal fatigue of the solder balls is frequently investigated by means of the finite element method. Various modeling assumptions and simplifications are common to restrict the calculation effort. Some of them, like geometric modeling assumptions, assumptions concerning the homogeneity of the cyclic temperature fields, simplified creep characterization of solder, and the related application of Manson-Coffin failure criteria, are discussed in the paper. The packages chosen for detailed analyses are a PBGA 272 and a FC-CSP 230.

Interface Adhesion and Reliability of Microsystem Packaging

2003 ◽  
Vol 782 ◽  
Author(s):  
Marvin I. Francis ◽  
Kellen Wadach ◽  
Satyajit Walwadkar ◽  
Junghyun Cho
Keyword(s):  
High Performance ◽  
Flip Chip ◽  
Coefficient Of Thermal Expansion ◽  
Dissimilar Materials ◽  
Strain Energy Release ◽  
Interface Adhesion ◽  
Curing Conditions ◽  
Chip Technology ◽  
Solder Balls ◽  
Cte Mismatch

ABSTRACTFlip-chip technology is becoming one of the most promising packaging techniques for high performance packages. Solder balls are used as the connection technique in the flip-chip method and the connections are reinforced by filling in the spacing between the chip and substrate with underfill. The function of the underfill is to reduce the stresses in the solder joints caused by a coefficient of thermal expansion (CTE) mismatch. The presence of polymeric underfill material will, however, make the flip-chip packaging system susceptible to interfacial failure. Thus, the purpose of this study is to examine the interfacial delamination between the dissimilar materials in order to increase the reliability of the flip-chip interconnection method, and to understand the effect of underfill curing conditions on the interface adhesion. In particular, we use a linear elastic fracture mechanics (LEFM) approach to assess interfacial toughness. For this purpose, four-point bending testing is performed to determine a critical strain energy release rate, Gc. In addition, nano-indentation testing equipped with atomic force microscope (AFM) is employed to determine structure and properties of the underfill layer.

Machine Learning Assisted Signal Analysis in Acoustic Microscopy for Non-Destructive Defect Identification

2019 ◽  
Author(s):  
Michael Kögel ◽  
Sebastian Brand ◽  
Frank Altmann
Keyword(s):  
Machine Learning ◽  
Failure Analysis ◽  
Human Error ◽  
Flip Chip ◽  
Acoustic Microscopy ◽  
Classification Model ◽  
Supervised Machine Learning ◽  
Machine Learning Techniques ◽  
Scanning Acoustic Microscopy ◽  
Chip Technology

Abstract Signal processing and data interpretation in scanning acoustic microscopy is often challenging and based on the subjective decisions of the operator, making the defect classification results prone to human error. The aim of this work was to combine unsupervised and supervised machine learning techniques for feature extraction and image segmentation that allows automated classification and predictive failure analysis on scanning acoustic microscopy (SAM) data. In the first part, conspicuous signal components of the time-domain echo signals and their weighting matrices are extracted using independent component analysis. The applicability was shown by the assisted separation of signal patterns to intact and defective bumps from a dataset of a CPU-device manufactured in flip-chip technology. The high success-rate was verified by physical cross-sectioning and high-resolution imaging. In the second part, the before mentioned signal separation was employed to generate a labeled dataset for training and finetuning of a classification model based on a one-dimensional convolutional neural network. The learning model was sensitive to critical features of the given task without human intervention for classification between intact bumps, defective bumps and background. This approach was evaluated on two individual test samples that contained multiple defects in the solder bumps and has been verified by physical inspection. The verification of the classification model reached an accuracy of more than 97% and was successfully applied to an unknown sample which demonstrates the high potential of machine learning concepts for further developments in assisted failure analysis.

scholarly journals Contrast Mechanisms for Tumor Cells by High-frequency Ultrasound

2018 ◽  
Vol 12 (1) ◽  
pp. 105-119
Author(s):  
Yada Juntarapaso ◽  
Chiaki Miyasaka ◽  
Richard L. Tutwiler ◽  
Pavlos Anastasiadis
Keyword(s):  
Elastic Properties ◽  
High Frequency ◽  
Angular Spectrum ◽  
Wave Theory ◽  
Biomechanical Properties ◽  
Acoustic Microscopy ◽  
High Frequency Ultrasound ◽  
Volumetric Imaging ◽  
4D Imaging ◽  
Contrast Mechanisms

Scanning Acoustic Microscopy (SAM) is a powerful technique for both the non-destructive determination of mechanical and elastic properties of biological specimens and for the ultrasonic imaging at a micrometer resolution. The implication of biomechanical properties during the onset and progression of disease has been established rendering a profound understanding of the relationship between mechanoelastic and biochemical signaling at a molecular level crucial. Computer simulation algorithms were developed for the generation of images and the investigation of contrast mechanisms in high-frequency and ultra-high frequency SAM. Furthermore, we determined the mechanical and elastic properties of HeLa and MCF-7 cells. Algorithms for simulatingV(z)responses were developed based on the ray and wave theory (angular spectrum). Theoretical simulations for high-frequency SAM array designs were performed with the Field II software. In these simulations, we applied phased array beam formation and dynamic apodization and focusing. The purpose of our transducer simulations was to explore volumetric imaging capabilities. The novel transducer arrays designed in this research aim at improving the performance of SAM systems by introducing electronic steering and hence, allowing for the 4D imaging of cells and tissues.

scholarly journals High-Frequency Time-Resolved Scanning Acoustic Microscopy for Biomedical Applications

2018 ◽  
Vol 12 (1) ◽  
pp. 69-85 ◽  
Author(s):  
Pavlos Anastasiadis ◽  
Pavel V. Zinin
Keyword(s):  
High Frequency ◽  
Focused Ultrasound ◽  
Ultrasound Biomicroscopy ◽  
Acoustic Microscopy ◽  
High Frequency Ultrasound ◽  
Time Resolved ◽  
Biochemical Processes ◽  
Wide Range ◽  
Progression Of Disease ◽  
Frequency Ultrasound

High-frequency focused ultrasound has emerged as a powerful modality for both biomedical imaging and elastography. It is gaining more attention due to its capability to outperform many other imaging modalities at a submicron resolution. Besides imaging, high-frequency ultrasound or acoustic biomicroscopy has been used in a wide range of applications to assess the elastic and mechanical properties at the tissue and single cell level. The interest in acoustic microscopy stems from the awareness of the relationship between biomechanical and the underlying biochemical processes in cells and the vast impact these interactions have on the onset and progression of disease. Furthermore, ultrasound biomicroscopy is characterized by its non-invasive and non-destructive approach. This, in turn, allows for spatiotemporal studies of dynamic processes without the employment of histochemistry that can compromise the integrity of the samples. Numerous techniques have been developed in the field of acoustic microscopy. This review paper discusses high-frequency ultrasound theory and applications for both imaging and elastography.

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