Die Bonding Issues on Silicon Carbide Diodes

2006 ◽  
Vol 527-529 ◽  
pp. 875-878 ◽  
Author(s):  
Seung Yong Lee ◽  
Jang Sub Lee ◽  
Tae Hong Kim ◽  
Sung Yong Choi ◽  
Hak Jong Kim ◽  
...  
Keyword(s):  
Shear Test ◽  
Vertical Structure ◽  
Optical Microscope ◽  
Device Fabrication ◽  
Cleaning Process ◽  
X Ray ◽  
The Third ◽  
Bottom Side ◽  
Die Bonding

We report on the die bonding processes and how the surface roughness and metallization schemes affect the processes of die bonding in 4H-SiC device fabrication using a soldering test and die shear test (DST) with differently prepared 4H-SiC samples. The first set of samples (FZ#1 and FZ#2) was capped with sequentially evaporated Ti and Au on an annealed Ni layer. The second set of samples (FZ#3 and FZ#4) and the third set of samples (FZ#5 and FZ#6) were prepared by 4μm-thick Au electroplating on an annealed Ni layer and an un-annealed Ni layer, respectively. The quality of the soldering, such as the solder coverage, void, and adhesion, was characterized by optical microscope, X-ray microprobe, and DST. We found that the samples (FZ#4 and FZ#6) deposited by Au electroplating on C-face (bottom-side) 4H-SiC provided a satisfactory result for the tests of solder coverage, void, and DST and also realized the cleaning process prior to the electroplating and soldering was the most crucial in the die packaging processes of vertical structure devices. The void fraction measured by X-ray microprobe for the samples, FZ#4 and FZ#6 was 2.2% (average for 5 samples) and 0.8% (average for 3 samples), respectively.

Optimising the Growth of Few-Layer Graphene on Silicon Carbide by Nickel Silicidation

2013 ◽  
Vol 740-742 ◽  
pp. 121-124 ◽  
Author(s):  
Enrique Escobedo-Cousin ◽  
Konstantin Vassilevski ◽  
Toby Hopf ◽  
Nick G. Wright ◽  
Anthony O’Neill ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Sample Surface ◽  
Device Fabrication ◽  
Solid Phase Epitaxy ◽  
X Ray ◽  
Graphene Films ◽  
Few Layer Graphene ◽  
The Impact

Few-layers graphene films (FLG) were grown by local solid phase epitaxy on a semi-insulating 6H-SiC substrate by annealing Ni films deposited on the Si and C-terminated faces of the SiC. The impact of the annealing process on the final quality of the FLG films is studied using Raman spectroscopy. X-ray photoelectron spectroscopy was used to verify the presence of graphene on the sample surface. We also demonstrate that further device fabrication steps such as dielectric deposition can be carried out without compromising the FLG films integrity.

scholarly journals Deburring Method of Aluminum Mould Produced by Milling Process for Microfluidic Device Fabrication

2021 ◽  
Vol 6 (1) ◽  
pp. 123-140
Author(s):  
Kushendarsyah Saptaji ◽  
Farid Triawan ◽  
Tong Keong Sai ◽  
Asmelash Gebremariam
Keyword(s):  
Stainless Steel ◽  
Microfluidic Device ◽  
Laser Scanning ◽  
Optical Microscope ◽  
Milling Process ◽  
Device Fabrication ◽  
Ductile Metals ◽  
Slot Milling ◽  
Micro Scale

The existence of top burrs in micro-scale features produced by milling process can deteriorate the surface quality of a product. Ductile metals, such as aluminum alloys, are prone to suffer from top burrs formation after a slot-milling process. A brief review on the state-of-the-art of burr removal process in micro-scale milling is provided in this paper. Various deburring methods were reportedly able to remove the burrs in micro-scale features, however a much simpler method is still needed. In the present work, a deburring process by stainless steel end brushing is introduced for aluminum mould used in microfluidic device fabrication. The micro-scale features are produced by slot-milling process followed by the deburring process. The deburred moulds are then visually observed using optical microscope and Scanning Electron Microscope (SEM) and the average surface roughness and its features profile are measured using 3D Laser Scanning Confocal Microscope. As a result, the proposed deburring method can successfully remove the top burrs, as indicated by a height reduction of about 21% due to the removal action by the brush. Hence, a burr-free embossing mould with complex shape channel features can be produced by milling and by applying a simple deburring process using stainless steel end brush.

X-Ray Study of Strained and Strain Balanced Superlattice Materials

2011 ◽  
Vol 1318 ◽  
Author(s):  
Natee Johnson ◽  
Ruth Choa ◽  
Liwei Cheng ◽  
Fow-Sen Choa
Keyword(s):  
Quantum Cascade Lasers ◽  
Device Fabrication ◽  
Focal Plane Arrays ◽  
Scanning Tunneling ◽  
Ir Detectors ◽  
X Ray ◽  
Superlattice Structure ◽  
Strained Layer Superlattice ◽  
Electron Microscopes

ABSTRACTNano-scale superlattice (SL) based devices, such as quantum cascade lasers QCLs, have recently become very important due to their capability to identify toxic and explosive chemicals. In manufacturing these Mid-IR photonic devices, atomic-level scanning tunneling microscopes (STM) and transmission electron microscopes (TEM) have been used to characterize the growth quality of superlattice wafers. However, these methods yield observations that are localized and cannot view the entire structure and even now we have not been able to correlate these measured crystal lattice images with device performance. The x-ray scanning technique has greater likelihood of success given that it can observe not only the localized, but also the entire superlattice structure. By extracting special features and key parameters in x-ray diffraction (XRD) patterns, the epitaxial quality of QCL superlattices can be evaluated and correlated to the performance of fabricated QCL devices. We can then differentiate and classify different grades of wafers before starting device fabrication and testing.Such an example of the usefulness of XRD can be found with strain-balanced superlattices, such as InGaAs/InAlAs, where there is notable decrease in laser performance after relaxation. It can also be found with type-II InAs/GaSb strained layer superlattice, which is currently the best candidate for room temperature mid-IR detectors and focal plane arrays. Experimentally measured x-ray patterns are compared to simulation results and problem sources are identified.

Der Einfluß der Inaktivitätsosteoporose auf die szintigraphische Darstellung knöcherner Verletzungen im Bereich des Handgelenks

1989 ◽  
Vol 28 (04) ◽  
pp. 124-128 ◽  
Author(s):  
J. Spitz ◽  
N. Clemenz ◽  
K. Tittel ◽  
H. Weigand
Keyword(s):  
Bone Scintigraphy ◽  
Plaster Cast ◽  
Scaphoid Bone ◽  
X Ray ◽  
The Third ◽  
High Level ◽  
Clinical Conditions ◽  
Rate Of Accumulation

In addition to its established oncological indications the sensitivity of bone scintigraphy is of steadily increasing significance in traumatology. Inactivity- induced osteoporosis plays a major role during the immobilization period in the plaster cast. In the region of the joints remodelling intensity may reach such a high level that the non-injured bone shows a higher rate of accumulation than the fracture. This process already begins between the third and fourth week of immobilization. The highest uptake is found after fracture of the scaphoid bone at the end of twelve weeks of immobilization. Control scintigraphies at intervals of several days are indicated to differentiate between various clinical conditions (pseudoarthrosis, activated osteoarthrosis, algodystrophy in case of doubtful x-ray results).

Pengaruh Pemberian Moringa oleifera Terhadap Kuantitas dan Kualitas Semen Sapi Peranakan Ongole

2020 ◽  
Vol 7 (2) ◽  
pp. 119
Author(s):  
Lukman Affandhy ◽  
Muchamad Luthfi ◽  
Dian Ratnawati ◽  
Frediansyah Firdaus
Keyword(s):  
Data Analysis ◽  
Analysis Of Variance ◽  
Research Method ◽  
Moringa Oleifera ◽  
The Third ◽  
Randomized Design ◽  
Leaf Powder ◽  
Completely Randomized Design ◽  
Second Period

ABSTRAK  Penelitian bertujuan untuk mengetahui pengaruh pemberian bubuk daun Moringa oleifera (MO) terhadap kuantitas dan kualitas semen sapi peranakan ongole (PO). Metode penelitian menggunakan percobaan lapang dengan rancangan acak lengkap dengan tiga perlakuan pemberian MO sebesar 0 kg/ekor/hari (P1); 0,05 kg/ekor/hari (P2) dan 0,1 kg/ekor/hari (P3). Analsis data menggunakan one way analysis of variance. Masing-masing perlakuan terdiri atas empat ekor dengan tiga periode pengamatan sebagai ulangan, yaitu periode pertama dan ketiga tanpa MO, dan periode kedua diberikan MO pada P2 dan P3. Hasil penelitian menunjukan bahwa volume dan pH semen perlakuan P1, P2 dan P3 tidak berbeda semua periode pengamatan. Motilitas massa spermatozoa P2 dan P3 periode kedua dan ketiga menunjukan nilai +++ berbeda nyata (P<0,05) dibandingkan dengan P1 (++); motilitas individu  perlakuan P1 menunjukkan nilai terendah 60,56±2,94 % (P<0,05) dibandingkan P2 dan P3 pada periode kedua dan ketiga (75,50±2,29 dan 72,50±2,34%). Konsentrasi spermatozoa P2 dan P3 periode kedua dan ketiga menunjukkan rata-rata  >1.350 juta/ml berbeda nyata (P<0,05) daripada P1 (876±152juta/ml), sedangkan total spermatozoa motil menunjukkan nilai tertinggi 5.647±829 juta/ml pada P3 periode kedua.Viabilitas spermatozoa P2 dan P3 menunjukkan nilai >88-89 % beda nyata (P<0,05) daripada P1 (<84 %) pada periode kedua dan ketiga, sedangkan nilai abnormalitas spermatozoa yang terbaik adalah P2 sebesar 4,30% pada periode kedua dan P3 sebesar 5,33% pada periode ketiga. Disimpulkan pemberian bubuk daun MO dengan dosis 0,1 kg/ekor/hari dapat memperbaiki kuantitas dan kualitas semen (viabilitas dan total spermatozoa motil) sapi pejantan PO.Kata kunci:  kuantitas dan kualitas semen, Moringa oleifera, sapi pejantan ABSTRACTThe research aimed to determine the effect of Moringa oleifera (MO) leaf powder on the quantity and quality of semen of ongole crossbreed. The research method used was a field experiment with a completely randomized design with three treatments giving MO of 0 kg/head/day (P1); 0.05 kg/head/day (P2) and 0.1 kg/head/day (P3). Each treatment consisted of four heads with three periods of observation as replications, namely the first and third periods without MO, and the second period was given MO on P2 and P3. Data analysis used a one-way analysis of variance. The results showed that the volume and pH of semen treated P1, P2, and P3 didn’t different in all observation periods. The second and third period spermatozoa mass motility of P2 and P3 showed that the value of +++ was significantly different (P<0.05) compared to P1 (++); Individual motility of P1 treatment showed the lowest value 60,56±2,94 % (P<0.05) compared to P2 and P3 in the second and third periods (75,50±2,29 and 72,50±2,34%). The second and third periods of P2 and P3 spermatozoa concentrations showed an average of >1,350 million/cc significantly different (P<0.05) than P1 (876±152 million/cc), while the total motile spermatozoa showed the highest value of 5,647±829 million/cc in the second period P3. The spermatozoa viability of P2 and P3 showed values >88-89% significantly different (P<0.05) than P1 (<84%) in the second and third periods, while the best spermatozoa abnormalities were P2 at 4.30% in the second period and P3 at 5.33% in the third period. It was concluded that the giving of MO leaf powder at a dose of 0,1 kg/head/day could improve the quantity and quality of semen (viability and total motile spermatozoa) of Ongole Crossbreed bulls. Keywords: bulls, Moringa oleifera, quantity and quality of semen

X-ray fluorescence determination of zinc sulfate in acidic zinc plating electrolyte

2020 ◽  
Vol 86 (10) ◽  
pp. 18-22
Author(s):  
K. N. Vdovin ◽  
K. G. Pivovarova ◽  
N. A. Feoktistov ◽  
T. B. Ponamareva
Keyword(s):  
Zinc Sulfate ◽  
Zinc Coating ◽  
Electrolyte Composition ◽  
Complexometric Titration ◽  
X Ray ◽  
Fluorescence Determination ◽  
Zinc Plating ◽  
Zinc Determination

Zinc sulfate is the main component in the composition of the acidic zinc plating electrolyte. Deviation in the electrolyte composition from the optimum content leads to destabilization of the electrolysis process and deteriorate the quality of the resulting zinc coating. The proper quality of a zinc coating obtained by galvanic deposition can be ensured only with timely monitoring and adjustment of the electrolyte composition. A technique of X-ray fluorescence determination of zinc (in terms of zinc sulfate) in an acidic zinc plating electrolyte is proposed. The study was carried out using an ARL Quant’X energy dispersive spectrometer (Thermo Fisher Scientific, USA) with a semiconductor silicon-lithium detector. The features of the spectrometer design are presented. The optimal parameters of excitation and detection of zinc radiation were specified when the electrolyte sample was diluted 1:1000. The ZnKα1 line was used as an analytical line. The plotted calibration graph is linear, the correlation coefficient being 0.999234. The results of zinc determination according to the developed method were compared with the data of the reference method of complexometric titration to prove the reliability of the procedure. The results are characterized by good convergence and accuracy. The proposed method of X-ray fluorescence zinc determination in a zinc plating electrolyte equals complexometric titration in the limiting capabilities and even exceeds the latter in terms of the simplicity of sample preparation and rapidity. The developed method of X-ray fluorescence determination of zinc is implemented in analysis of the electrolyte used in the continuous galvanizing unit at «METSERVIS LLC».

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

An Overview of 300 mm SOI Starting Wafer Quality and Its Yield Detractors

2005 ◽  
Author(s):  
Pei Y. Tsai ◽  
Junedong Lee ◽  
Paul Ronsheim ◽  
Lindsay Burns ◽  
Richard Murphy ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Device Fabrication ◽  
Sampling Plan ◽  
Silicon On Insulator ◽  
Manufacturing Processes ◽  
Circuit Performance ◽  
Characterization Techniques ◽  
Wafer Manufacturing

Abstract A stringent sampling plan is developed to monitor and improve the quality of 300mm SOI (silicon on insulator) starting wafers procured from the suppliers. The ultimate goal is to obtain the defect free wafers for device fabrication and increase yield and circuit performance of the semiconductor integrated circuits. This paper presents various characterization techniques for QC monitor and examples of the typical defects attributed to wafer manufacturing processes.

Typical errors and violations of biotechnics of artificial breeding of pacific salmon

2020 ◽  
pp. 13-23
Author(s):  
Ekaterina Grinberg
Keyword(s):  
Production Process ◽  
Preventive Measures ◽  
Pacific Salmon ◽  
Fish Farming ◽  
Important Condition ◽  
The Third ◽  
Fish Breeding ◽  
Artificial Breeding ◽  
Strict Compliance

In two parts of the article, more than 70 errors and violations of the Biotechnics of artificial breeding of Pacific salmon in salmon hatcheries are collected and summarized, which lead to an immediate or delayed deterioration of the quality of reared fry and a decrease in their survival rate. Deviations from the biological basis of fish farming are shown and possible consequences of such errors or violations are predicted. In the first part of the article (#7,2020) there were General errors (throughout the entire fish-breeding process), as well as violations of Biotechnics during the work with producers, collecting eggs and preparing them for incubation, in the second part-violations of Biotechnics during the incubation of eggs, holding pre-larvae, rearing and release of young. Their correction, prevention or minimization of consequences will significantly improve the quality of sexual products and offspring from producers, increase the linear and weight gain of juveniles during rearing, improve the coefficient of feed payment, reduce the time of rearing, improve the epizootic situation by developing immunity in fry and mobilizing other protective reactions of their body, significantly reduce waste at all stages of the production process, increasing survival by 10–15%. In conclusion, it is noted that the first and most important condition for an efficient salmon hatchery is the creation of optimal environmental conditions at each stage of the production process. The second condition is strict compliance with the Biotechnics of artificial salmon breeding and the complex of veterinary and sanitary, fish-breeding and meliorative and therapeutic and preventive measures. The third is the availability of competent specialists who regularly improve their skills in accredited Universities to implement, control and manage the first two conditions.

OSTEOPOROSIS AND RISK FACTORS IN THE PATIENTS ON CHRONIC HEMODIALYSIS

2015 ◽  
pp. 50-58
Author(s):  
Thi Dung Nguyen ◽  
Tam Vo
Keyword(s):  
Quality Of Life ◽  
Risk Factors ◽  
Bone Density ◽  
Region Of Interest ◽  
Cross Sectional Study ◽  
Chronic Hemodialysis ◽  
Cross Sectional ◽  
X Ray ◽  
Density Reduction

Background: The patients on hemodialysis have a significantly decreased quality of life. One of many problems which reduce the quality of life and increase the mortality in these patients is osteoporosis and osteoporosis associated fractures. Objectives: To assess the bone density of those on hemodialysis by dual energy X ray absorptiometry and to examine the risk factors of bone density reduction in these patients. Patients and Method: This is a cross-sectional study, including 93 patients on chronic hemodialysis at the department of Hemodialysis at Cho Ray Hospital. Results: Mean bone densities at the region of interest (ROI) neck, trochanter, Ward triangle, intertrochanter and total neck are 0.603 ± 0.105; 0.583 ± 0.121; 0.811 ± 0.166; 0.489 ± 0.146; 0.723 ± 0.138 g/cm2 respectively. The prevalences of osteoporosis at those ROI are 39.8%, 15.1%; 28%; 38.7%; and 26.9% respectively. The prevalences of osteopenia at those ROI are 54.8%; 46.3%; 60.2%; 45.2% and 62.7% respectively. The prevalence of osteopososis in at least one ROI is 52.7% and the prevalence of osteopenia in at least one ROI is 47.3%. There are relations between the bone density at the neck and the gender of the patient and the albuminemia. Bone density at the trochanter is influenced by gender, albuminemia, calcemia and phosphoremia. Bone density at the intertrochanter is affected by the gender. Bone density at the Ward triangle is influenced by age and albuminemia. Total neck bone density is influenced by gender, albuminemia and phosphoremia. Conclusion: Osteoporosis in patients on chronic hemodialysis is an issue that requires our attention. There are many interventionable risk factors of bone density decrease in these patients. Key words: Osteoporosis, DEXA, chronic renal failure, chronic hemodialysis

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