Basic Physics in Color-Coded EOS Metallization Failures (Differentiating between EOS and ESD)

1998 ◽  
Author(s):  
Leo G. Henry ◽  
J.H. Mazur
Keyword(s):  
Failure Analysis ◽  
Light Microscope ◽  
Structural Changes ◽  
Surface Oxide ◽  
Aluminum Surface ◽  
Surrounding Area ◽  
Die Surface ◽  
Basic Physics ◽  
Direct Contrast ◽  
Glass Interface

Abstract The task of differentiating precisely between EOS and ESD failures continues to be a challenging one for Failure Analysis Engineers. Electrical OverStress (EOS) failures on the die surface (burnt/fused metallization) of an IC can be characterized mainly by the discoloration at the site of the failures. This is in direct contrast to the lack of discoloration characteristic of ESD failures, which occur almost exclusively below the die surface (oxide and junction failures). To aid in this distinction, this paper attempts to present the underlying physics behind the discoloration produced in the EOS failures. For the EOS failures, the metal fuses due to the longer pulse widths (sec to msec), while for the ESD failures, the silicon melts because of the shorter pulse widths (< < 500 nsec) and higher energy. After EOS, the aluminum surface becomes dark and rough and the oxide in the surrounding area becomes deformed and distorted, resulting in the discoloration observed in the light microscope. This EOS discoloration could be due to one or more of the following: 1) morphological and structural changes at the metal/glass interface and the glass itself; 2) changes in the thickness and scattering behavior of the glass and metal in the failed areas.

Backside Mechanical Preparation Methodology for Effective Failure Analysis on Small and Non-Exposed Die Paddle Package

2018 ◽  
Author(s):  
Ong Pei Hoon ◽  
Ng Kiong Kay ◽  
Gwee Hoon Yen
Keyword(s):  
Failure Analysis ◽  
Chemical Etching ◽  
Chemical Resistance ◽  
Etching Time ◽  
Lead Frame ◽  
Front Side ◽  
Electrical Measurements ◽  
Mechanical Preparation ◽  
Die Surface ◽  
Copper Lead

Abstract Chemical etching is commonly used in exposing the die surface from die front-side and die backside because of its quick etching time, burr-free and stress-free. However, this technique is risky when performing copper lead frame etching during backside preparation on small and non-exposed die paddle package. The drawback of this technique is that the copper leads will be over etched by 65% Acid Nitric Fuming even though the device’s leads are protected by chemical resistance tape. Consequently, the device is not able to proceed to any other further electrical measurements. Therefore, we introduced mechanical preparation as an alternative solution to replace the existing procedure. With the new method, we are able to ensure the copper leads are intact for the electrical measurements to improve the effectiveness and accuracy of physical failure analysis.

Interfacial Delamination in Plastic Encapsulated Integrated Circuits (Pics)

1996 ◽  
Vol 445 ◽  
Author(s):  
Nickolaos Strifas ◽  
Aris Christou
Keyword(s):  
Integrated Circuits ◽  
Failure Analysis ◽  
Stress Corrosion ◽  
Integrated Circuit ◽  
Point Of View ◽  
Acoustic Microscopy ◽  
Electrical Performance ◽  
Premature Failure ◽  
Interfacial Delamination ◽  
Die Surface

AbstractThe reliability of plastic packaged integrated circuits was assessed from the point of view of interfacial mechanical integrity. It is shown that the effect of structural weaknesses caused by poor bonding, voids, microcracks or delamination may not be evident in the electrical performance characteristics, but may cause premature failure. Acoustic microscopy (C-SAM) was selected for nondestructive failure analysis of the plastic integrated circuit (IC) packages. Integrated circuits in plastic dual in line packages were initially subjected to temperature (25 °C to 85 °C) and humidity cycling (50 to 85 %) where each cycle was of one hour duration and for over 100 cycles and then analyzed. Delamination at the interfaces between the different materials within the package, which is a major cause of moisture ingress and subsequent premature package failure, was measured. The principal areas of delamination were found along the leads extending from the chip to the edge of the molded body and along the die surface itself. Images of the 3-D internal structure were produced that were used to determine the mechanism for a package failure. The evidence of corrosion and stress corrosion cracks in the regions of delamination was identified.

Structural changes of radial forging die surface during service under thermo-mechanical fatigue

2009 ◽  
Vol 527 (1-2) ◽  
pp. 98-102 ◽  
Author(s):  
Fardin Nematzadeh ◽  
Mohammad Reza Akbarpour ◽  
Amir Hosein Kokabi ◽  
Seyed Khatiboleslam Sadrnezhaad
Keyword(s):  
Structural Changes ◽  
Radial Forging ◽  
Mechanical Fatigue ◽  
Die Surface ◽  
Forging Die

scholarly journals Magnitude of thoracic spine deformity affecting morphologial characteristics of paraspinal muscles in patients with severe idiopathic scoliosis

2021 ◽  
Vol 27 (1) ◽  
pp. 68-73
Author(s):  
E.N. Shchurova ◽  
◽  
G.N. Filimonova ◽  
S.O. Ryabykh ◽  
◽  
...  
Keyword(s):  
Idiopathic Scoliosis ◽  
Thoracic Spine ◽  
Light Microscope ◽  
Structural Changes ◽  
Morphological Characteristics ◽  
Surgical Correction ◽  
Control Group ◽  
Special Focus ◽  
Spine Deformity ◽  
Paraspinal Muscles

Introduction Morphological, biochemical and histopathological characteristics of paraspinal muscles have been well described in patients with idiopathic scoliosis. However, there is a paucity of literature on morphological picture of paraspinal muscles in patients with severe idiopathic scoliosis. Objective To explore how the magnitude of thoracic spine deformity affects morphological characteristics of paraspinal muscles in patients with severe idiopathic scoliosis. Material and methods A total 21 patients with idiopathic scoliosis were reviewed. The patients were assigned to two groups depending on magnitude of preoperative thoracic spine deformity. A major group consisted of patients with scoliosis of ≥ 60º (n = 11) and control group included patients with a curve < 60º (n=10). Biopsy samples were taken from muscle fragments (multifidus muscle) at the apex of the curve (major arc) at the Th6-Th10 level on the convex side while approaching to the posterior spinal structures during surgical correction of kyphoscoliosis using light microscope. The specimens were examined histologically with light microscope. Results Patients with severe idiopathic scoliosis (≥ 60º) showed evident muscle fiber atrophy and dystrophy of different extent. There were nucleus free areas and homogenized muscle fragments observed with connective tissue layers being swollen and frayed with multiple fibroblasts seen in nearly all the samples. Arterial walls were normally fibrotized. Structural changes ranged from minimal with a curve of 60º to degrading muscles with the fibers replaced by fat and connective tissues with a curve angle of 145º. Conclusion Morphological characteristics of paraspinal muscles have been shown to be severely affected by the magnitude of thoracic spine deformity in patients with severe idiopathic scoliosis. The findings should be considered in surgical correction of kyphoscoliosis with special focus on postoperative vascular and neurotropic therapy to allow wound healing and lower complication rate.

ChemInform Abstract: STRUCTURAL CHANGES OF SURFACE OXIDE LAYERS ON PALLADIUM

1982 ◽  
Vol 13 (32) ◽  
Author(s):  
T. CHIERCHIE ◽  
C. MAYER ◽  
W. J. LORENZ
Keyword(s):  
Structural Changes ◽  
Surface Oxide ◽  
Oxide Layers

scholarly journals Failure analysis of jet engine turbine blade

10.30544/138 ◽  
2016 ◽  
Vol 22 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Milan T. Jovanović ◽  
Vesna Maksimović ◽  
Ivana Cvijović-Alagić
Keyword(s):  
Electron Microscopy ◽  
Failure Analysis ◽  
Turbine Blade ◽  
Structural Changes ◽  
Rupture Life ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Jet Engine ◽  
Precision Casting ◽  
Life Tests

Jet engine turbine blade cast by investment precision casting of Ni-base superalloy, which failed during exploatation, was the subject of investigation. Failure analysis was executed applying optical microscopy (OM), transmission electron microscopy (TEM) using replica technique, scaning electron microscopy (SEM) and stress rupture life tests. On the ground of obtained results it was concluded that the failure occurred as a result of structural changes caused by turbine blade overheating above the exploitation temperature.

The Investigation of Oven Contamination and Corresponding Methodology

2019 ◽  
Author(s):  
W. F. Hsieh ◽  
Henry Lin ◽  
Vincent Chen ◽  
Jun Liu ◽  
Irene Ou ◽  
...  
Keyword(s):  
Contact Angle ◽  
Failure Analysis ◽  
Pdms Layer ◽  
Root Cause ◽  
Contamination Effect ◽  
Die Surface ◽  
Contamination Event ◽  
Set Up ◽  
In The Beginning ◽  
Secondary Ion

Abstract Contamination and particle reduction are critical to semiconductor process control. Lots of failure analysis had been focused on finding the root cause of the particle and contamination. The particle and contamination effect were also easily found in circuit probing (CP) process, and therefore induced yield loss and wafer scrap. In the first part of this paper, an oven contamination case was studied. The second part of this paper focus on oven contamination monitoring. In the beginning, a die flying failure was papered at the stage of blue tape and die sawing. This event clearly indicated bad adhesion between die and plastic tape. This bad adhesion was suspected to be a particle/contamination layer formed on bad die surface. Three failure analysis (FA) approaches were performed to find out the root cause. The SEM/EDS result identified the main elements of big particle, but that is insufficient to identify the root cause. The OM/FTIR, however, showed the contamination may be related to polydimethylsiloxane (PDMS). The last failure analysis was the time of fly Secondary Ion Mass Spectrometer (TOF-SIMS), the result confirmed that there was a thin PDMS layer formed on the contaminated bad die surface. The high temperature CP process induced PDMS is believed to be the contamination root cause. In order to prevent the oven contamination event, a methodology based on contact angle and wettability of Si matrix sample was set up for regular monitor in oven operation. The details of contact angle test (CAT) sample preparation, measurement and analysis results were also discussed in this paper.

Sample Preparation for Backside Failure Analysis Using Infrared Photoemission Microscopy

1999 ◽  
Author(s):  
Alastair Trigg ◽  
Peak Yong Loh
Keyword(s):  
Surface Roughness ◽  
Sample Preparation ◽  
Failure Analysis ◽  
Die Surface ◽  
Heavily Doped

Abstract For conventional photoemission microscopy the silicon is thinned to a few tens of micrometres for backside imaging since silicon is opaque in the visble part of the spectrum. However, at wavelengths greater than approximately 1050 nm, most silicon is effectively transparent. Hence, the use of an infrared photoemission microscope (IRPEM) operating at wavelengths of 1100 to 2500 nm, usually eliminates the need for thinning, except where the silicon is heavily doped. However, the plastic encapsulation of packaged devices must be removed and the die surface polished. A polishing system has been evaluated and optimised for this purpose. Surface roughness (Ra) of 1 nm or better was obtained. Representative applications are shown and discussed.

Mechanical/Plasma Decapsulation Method and Thermal Finite-Element Analysis Provide Explanation for SMB Zener Failures

1998 ◽  
Author(s):  
Kent Kime ◽  
Chuck Reed ◽  
Joe Di Silvestro ◽  
Ruth Ruiz ◽  
Simon Keeton ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Failure Analysis ◽  
Recent Change ◽  
Test Duration ◽  
Zener Diode ◽  
Element Analysis ◽  
Test Parameters ◽  
Die Surface ◽  
Transient Thermal

Abstract Failure analysis and finite-element analysis were used in conjunction to determine the cause of zener diode failures. A mechanical/plasma depot method was developed for the plastic-encapsulated SMB package and used to observe the presence of remelted extruded solder material on the die surface. That material provided a conductive path which manifested electrically as premature breakdown. Transient-thermal finite-element analysis was then used to show that a recent change of in-house surge test parameters could result in part temperatures during surge testing in excess of the solder melting temperature. These efforts lead to a respecification of the in-house surge test duration which resolved the problem.

Preparation and Characterization of LAS Glass Based Materials for Dental Applications

2016 ◽  
Vol 702 ◽  
pp. 28-31 ◽  
Author(s):  
Silvia Barbi ◽  
Monia Montorsi ◽  
Consuelo Mugoni ◽  
Cristina Siligardi
Keyword(s):  
Flexural Strength ◽  
Glass Ceramic ◽  
Structural Changes ◽  
Industrial Process ◽  
Ceramic Materials ◽  
Ceramic Support ◽  
Natural Teeth ◽  
Ceramic Glass ◽  
Glass Interface ◽  
Dental Applications

Glass ceramic materials are widely used in dental application because of their strong similarity with natural teeth. In this study LAS glass ceramic/glass materials were prepared by glazing processing and characterized in terms of mechanical flexural strength. The selected glass ceramic support derives from an industrial process. Different glasses were applied to the glass ceramic support in order to investigate firstly their effect on the glass ceramic/glass interface and secondly how these structural changes are correlated to the flexural strength property. Different thermal cycles were applied to the glass ceramic in order to promote the increasing of mechanical flexural strength. Preliminary results clearly points out that the application of a glass on the support leads to the decrease of the flexural strength if compared to the materials without any coating applied.

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