Failure Analysis of Plastic Packaged GaAs and AlGaAs/GaAs LEDs

1999 ◽  
Author(s):  
Patricia F. Mead ◽  
Melody Burch ◽  
Patrick McCluskey ◽  
F. G. Johnson
Keyword(s):  
Failure Analysis ◽  
Light Output ◽  
Environmental Scanning Electron Microscopy ◽  
Electrical Characterization ◽  
Electrical Performance ◽  
Environmental Scanning ◽  
Degradation Mechanisms ◽  
Analysis Techniques ◽  
Simple Screening

Abstract Failure and degradation mechanisms of plastic packaged LEDs that have been subjected to high levels of moisture, current bias, and elevated temperature conditions have been investigated and analyzed. The investigation included electrical characterization and a variety of failure analysis techniques including photoluminescence (PL), electroluminescence (EL), cathodoluminescence (CL), and environmental scanning electron microscopy (ESEM). Our results highlight the usefulness of simple screening techniques to monitor the quality of newly manufactured LED packages. Our results also indicate that for AlGaAs structures, degradation of the light output and electrical performance involves a complex interaction between temperature, relative humidity at the LED surface and voltage bias.

Semiconductor Wear Out at Nuclear Power Plants

2000 ◽  
Author(s):  
James B. Riddle
Keyword(s):  
Failure Analysis ◽  
Case Studies ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Light Output ◽  
Analysis Techniques ◽  
Root Cause ◽  
Corrective Actions ◽  
Control Circuits

Abstract This paper will examine semiconductor wear out at San Onofre Nuclear Generation Station (SONGS). The topics will include case studies, failure mechanisms, diagnostic techniques, failure analysis techniques and root cause corrective actions. Nuclear power plants are unique in that instrumentation and control circuits are continuously energized, are periodically tested, and have been in operation for greater than 25 years. Root cause evaluations at SONGS have identified numerous semiconductor failures due to wear out. Case studies include light output deterioration in opto-isolators, junction alloying failures of transistors and integrated circuits and parametric shifts in operational amplifiers. In most cases the devices do not fail catastrophically but degraded to the point of circuit level functional failure. Failure analysis techniques include circuit analysis, board level troubleshooting to identify the degraded components. Intermittent failures require power cycling, thermal cycling, and long term monitoring to identify the responsible components. Corrective actions for semiconductor wear out at SONGS include enhanced monitoring and proactive change out of identified part types.

scholarly journals Synergism of Mud Cake Modifier with Forming Agent of Agglomerated Cake at Cement-Formation Interface with MTA Method

2013 ◽  
Vol 7 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Jun Gu ◽  
Bo Wang ◽  
Jibiao He ◽  
Qinggui Wang ◽  
Guiping Wen ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Cement Slurry ◽  
Gas Well ◽  
Ionic Groups ◽  
Mud Cake ◽  
Calcium Silicate Hydrates

Based on the method of mud cake to agglomerated cake (MTA), the synergism of mud cake modifier (MCM) with forming agent of agglomerated cake (FAAC) in oil and gas well is studied by means of X-ray diffraction (XRD), environmental scanning electron microscopy (ESEM) and atomic absorption spectroscopy (AAS). The results show that the mud cake with MCM at cement-formation interface (CFI) is corroded by FAAC. And the corrosion spots and cracks are formed. The glassy substance in mud cake is depolymerized by hydrated ions from oilwell cement slurry through these spots and cracks. The soluble ionic groups in mud cake form. The diagenesis in mud cake at CFI occurs. The calcium silicate hydrates (CSH), ettringite, film zeolite, rod zeolite and natrolite gels in mud cake generate. Ultimately, it achieves the integrated solidification and cementation (ISC) among cement paste, agglomerated cake and formation at CFI. This paper explains why the isolation quality of CFI is improved by the MTA method.

In environmental Scanning Electron Microscopy, the secondary electron signal reveals surface information not accessible by conventional backscattered electron signals

1989 ◽  
Vol 47 ◽  
pp. 78-79
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
High Vacuum ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Specimen Preparation ◽  
Dynamic Events ◽  
Backscattered Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Environmental scanning electron microscopes (ESEM) operate at high as well as at low vacuum (<2.5 kPa: ~20 Torr) but utilize all advantages of conventional high vacuum SEM (large specimen size, high depth of focus and specimen tilt capability, TV-rate scanning for imaging dynamic events). They have the advantage of imaging wet specimens as well as insulators without the need of any specimen preparation. Previously, environmental scanning microscopy was restricted to the BSE signal collected with BSE detectors. SE signals cannot be collected with the Everhart-Thornley detector because it cannot operate at low vacuum. Using positively biased electron collectors, it is now possible to collect an SE signal. However, the origin and quality of this signal need to be further characterized.An ElectroScan ESEM was used equipped with SE and BSE detectors and operated at 7-30 kV with partial water pressures of 0.1-2.5 kPa (∼1-20 Torr).

Failure Mechanism and Root Cause Analysis of UBGA Solder Ball Contamination

2002 ◽  
Author(s):  
Vanessa Grace Martinez ◽  
Alden Almero ◽  
Gerard Gador
Keyword(s):  
Failure Analysis ◽  
Solder Ball ◽  
Contact Problems ◽  
Electrical Performance ◽  
Reflow Process ◽  
Analysis Techniques ◽  
Root Cause ◽  
Different Types ◽  
Solder Balls ◽  
Test Programming

Abstract A comparison of the electrical performance and effect of different types of flux to Micro Ball Grid Array (ìBGATM) solder ball quality was conducted. The units using no clean flux were found to exhibit opens failures during off-board testing and programming. Initial analysis conducted showed that the failures were due to contact problems between the solder balls and the test/programming sockets resulting from the presence of a transparent residue on the solder balls. In-depth failure analysis, in parallel with experiments conducted in the assembly line, was performed to determine the root cause of the solder ball contamination. Three failure analysis techniques were employed, namely: Scanning Electron Microscopy (SEM), Energy Dispersive Xray Analysis (EDX), and Fourier Transform Infrared (FTIR) Spectroscopy. An initial experiment was conducted to isolate the cause of the contamination by examining the different modules in the ìBGATM assembly. Failure analysis and experimental data proved that the opens failures were due to the no clean flux residue that was deposited on the surface of the solder ball after the reflow process.

Surface Quality of Human Corneal Lenticules After SMILE Assessed Using Environmental Scanning Electron Microscopy

2014 ◽  
Vol 30 (6) ◽  
pp. 388-393 ◽  
Author(s):  
Noël M. Ziebarth ◽  
Michael A. Lorenzo ◽  
Jessica Chow ◽  
Florence Cabot ◽  
Gregory J. R. Spooner ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Quality ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Scanning Electron

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

Detector strategies for environmental scanning electron microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1296-1297
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
High Vacuum ◽  
Environmental Scanning Electron Microscopy ◽  
Charge Carriers ◽  
Environmental Scanning ◽  
Surface Information ◽  
X Ray ◽  
Detector Electrode ◽  
Electrons And Ions ◽  
Low Energy Electrons ◽  
Environmental Sem

Environmental SEM operate at specimen chamber pressures of ∼20 torr (2.7 kPa) allowing stabilization of liquid water at room temperature, working on rugged insulators, and generation of an environmental secondary electron (ESE) signal. All signals available in conventional high vacuum instruments are also utilized in the environmental SEM, including BSE, SE, absorbed current, CL, and X-ray. In addition, the ESEM allows utilization of the flux of charge carriers as information, providing exciting new signal modes not available to BSE imaging or to conventional high vacuum SEM.In the ESEM, at low vacuum, SE electrons are collected with a “gaseous detector”. This detector collects low energy electrons (and ions) with biased wires or plates similar to those used in early high vacuum SEM for SE detection. The detector electrode can be integrated into the first PLA or positioned at any other place resulting in a versatile system that provides a variety of surface information.

PENGEMBANGAN MEDIA PEMBELAJARAN INTERAKTIF TEKNIK PEMESINAN BUBUT

2020 ◽  
Vol 6 (2) ◽  
pp. 169
Author(s):  
Philip Nababan ◽  
Efendi Napitupulu ◽  
R Mursid
Keyword(s):  
Student Learning ◽  
Learning Outcomes ◽  
Interactive Learning ◽  
Descriptive Analysis ◽  
Student Learning Outcomes ◽  
Field Trials ◽  
Student Responses ◽  
Analysis Techniques ◽  
Qualitative Descriptive

Abstrak: Penelitian ini bertujuan untuk: (1) Mengetahui tanggapan siswa terhadap kualitas media pembelajaran interaktif pada pembelajaran Teknik Pemesinan Bubut. (2) Mengetahui keefektifan media pembelajaran interaktif pada pembelajaran Teknik Pemesinan Bubut pada siswa program keahlian Teknik Pemesinan. Jenis penelitian ini adalah penelitian pengembangan. Data tentang kualitas produk pengembangan ini dikumpulkan dengan angket dan dianalisis dengan teknik analisis deskriptif kualiatatif. Hasil penelitian menunjukkan bahwa; (1) uji ahli materi pelajaran Teknik Pemesinan Bubut berada pada kualifikasi sangat baik (88,92%), (2) uji ahli desain pembelajaran berada pada kualifikasi sangat baik (85,21%), (3) uji ahli rekayasa perangkat lunak berada pada kualifikasi sangat baik (84,03%), (4) uji coba perorangan berada pada kualifikasi sangat baik (88,75%), (5) uji coba kelompok kecil berada pada kualifikasi sangat baik (91,35%) dan (5) uji coba lapangan berada pada kualifikasi sangat baik (88,31%). Hasil pengujian hipotesis membuktikan bahwa terdapat perbedaan antara hasil belajar siswa yang menggunakan media pembelajaran interaktif  dengan hasil belajar siswa yang menggunakan buku teks. Hal ini ditunjukkan dengan hasil pengolahan data diperoleh  thitung sebesar 4,68 dan ttabel sebesar 1,67 pada taraf kepercayaan 95 persen. Maka diperoleh bahwa thitung> ttabel. Disimpulkan bahwa  hasil belajar siswa yang menggunakan media pembelajaran interaktif dengan efektifitas sebesar 72,77 %. lebih tinggi dari hasil belajar siswa yang diajar dengan pembelajaran menggunakan buku teks dengan efektifitas sebesar 62,13%. Kata Kunci: media pembelajaran interaktif, teknik pemesinan bubut Abstract: This study aims to: (1) Determine student responses to the quality of interactive learning media on learning Lathe Machining Techniques. (2) Knowing the effectiveness of interactive learning media on learning of Machining Lathe in students of Machining Engineering expertise program. This type of research is development research. Data about the quality of this development product was collected by a questionnaire and analyzed by qualitative descriptive analysis techniques. The results showed that; (1) Lathe machining engineering subject matter expert test is in very good qualification (88.92%), (2) learning design expert test is in very good qualification (85.21%), (3) software engineering expert test is in in very good qualifications (84.03%), (4) individual trials were in very good qualifications (88.75%), (5) small group trials were in very good qualifications (91.35%) and (5 ) field trials are in very good qualifications (88.31%). Hypothesis testing results prove that there are differences between student learning outcomes using interactive learning media with student learning outcomes using textbooks. This is indicated by the results of data processing obtained by tcount of 4.68 and ttable of 1.67 at a confidence level of 95 percent. Then it is obtained that tcount> ttable. It was concluded that student learning outcomes using interactive learning media with an effectiveness of 72.77%. higher than student learning outcomes taught by learning to use textbooks with an effectiveness of 62.13%. Keywords: interactive learning media, lathe machining techniques

Failure Analysis of CDM-ESD Damage in a GaAs RFIC

2000 ◽  
Author(s):  
Amy Poe ◽  
Steve Brockett ◽  
Tony Rubalcava
Keyword(s):  
Radio Frequency ◽  
Failure Analysis ◽  
Integrated Circuit ◽  
Production Test ◽  
Analysis Techniques ◽  
Device Model ◽  
Charged Device ◽  
Subsequent Failure

Abstract The intent of this work is to demonstrate the importance of charged device model (CDM) ESD testing and characterization by presenting a case study of a situation in which CDM testing proved invaluable in establishing the reliability of a GaAs radio frequency integrated circuit (RFIC). The problem originated when a sample of passing devices was retested to the final production test. Nine of the 200 sampled devices failed the retest, thus placing the reliability of all of the devices in question. The subsequent failure analysis indicated that the devices failed due to a short on one of two capacitors, bringing into question the reliability of the dielectric. Previous ESD characterization of the part had shown that a certain resistor was likely to fail at thresholds well below the level at which any capacitors were damaged. This paper will discuss the failure analysis techniques which were used and the testing performed to verify the failures were actually due to ESD, and not caused by weak capacitors.

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