Microstructure for Printed Multilayer LTCC Tape of Different Paste Rheology

2010 ◽  
Vol 654-656 ◽  
pp. 2378-2381 ◽  
Author(s):  
Sabrina Mohd Shapee ◽  
Rosidah Alias ◽  
Ibrahim Azmi ◽  
Zulkifli Ambak ◽  
Mohd Zulfadli Mohamed Yusoff ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Screen Printing ◽  
Critical Parameter ◽  
Test Pattern ◽  
High Viscosity ◽  
Print Quality ◽  
Pattern Design ◽  
Silver Paste ◽  
Ceramic Tape ◽  
Scanning Electron

Screen printing is the most common method of transferring silver thick film paste to a low temperature co-fired ceramic tape. Silver paste with varying rheology will have a varying print quality. The effect of silver paste rheology on the microstructure is investigated. Although there are many parameters to be considered, this parameter is a critical parameter which will control the line width and roughness on the substrate. To study the effect of paste rheology, a test pattern design was printed on the Heraeus CT2000 LTCC tape using silver paste. Then the LTCC tape was stacked and laminated at pressure of 28 MPa and temperature of 65 oC for 10 minutes. The laminated sample then was fired up to 850 oC. The fired silver conductor printed on the LTCC tape then was analyzed. Prints were evaluated by scanning electron microscopy. It was found that silver paste with high viscosity produce a good microstructure.

scholarly journals 3D Bioprintability of Konjac Glucomannan Hydrogel

2019 ◽  
Vol 26 (1) ◽  
pp. 109-113
Author(s):  
Yulong WANG ◽  
Lu HAN ◽  
Jia YAN ◽  
Kun HU ◽  
Luhai LI ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Loss Modulus ◽  
High Viscosity ◽  
Konjac Glucomannan ◽  
Potential Applications ◽  
Scaffold Materials ◽  
Konjac Gum ◽  
Water Holding ◽  
Scanning Electron

Konjac glucomannan has potential applications in bio-printing, due to its unique properties, such as high viscosity, water-holding capacity and easy gelatinization. In this study, the rheological properties, i.e. the viscosity with changing the shear rate and the storage modulus G’ and loss modulus G’’ curve, of different concentrations of konjac gum hydrogel, were thoroughly measured. Furthermore, the pore sizes of various concentrated konjac gum hydrogel were observed under scanning electron microscopy (SEM). The bio-printability of konjac gum hydrogel was thoroughly evaluated using piston-type 3D bio-printer. It was showed that, 7% konjac gum hydrogel demonstrated the best bio-printability, which has potentially applied as scaffold materials in bio-printing field.

Sample Preparation to Observe The Straight And Flat Posture of Silkworm Embryo under Scanning Electron Microscopy via Glycerol Substitution Method

2014 ◽  
Vol 20 (3) ◽  
pp. 964-967
Author(s):  
Wenbin Liu ◽  
Chenzhao Li ◽  
Qi Zhang ◽  
Zhixin Lei ◽  
Yanqi Hou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ventral Side ◽  
High Viscosity ◽  
Preparation Technique ◽  
Preparation Process ◽  
Substitution Method ◽  
Simple Method ◽  
Sem Observation ◽  
Scanning Electron

AbstractIn the preparation process for scanning electron microscopy (SEM), flexed silkworm embryos typically assume several curled shapes with irregular postures that obscure morphological details during SEM observation. We describe a preparation technique based on glycerol substitution for better SEM visualization of straight and flat silkworm embryos. Glycerol has high viscosity, low vapor pressure, and sufficient electrical conductivity. Silkworm embryos were infiltrated with glycerol and arranged in a straight posture or flattened using a cover slip. Samples were directly observed by SEM without additional dehydration, drying, or coating procedures. The complete ventral side could be easily viewed in one image. Recoating alleviated the charging phenomenon. This represents a simple method for preparation of straight and flat samples from curled biological specimens for SEM observation.

Rapid Prototyping of Micropatterned Substrates Using Conventional Laser Printers

2002 ◽  
Vol 17 (7) ◽  
pp. 1559-1562 ◽  
Author(s):  
Michael L. Branham ◽  
Roger Tran-Son-Tay ◽  
Christopher Schoonover ◽  
Patrick S. Davis ◽  
Susan D. Allen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rapid Prototyping ◽  
Test Pattern ◽  
Research Community ◽  
Laser Printer ◽  
Palo Alto ◽  
Hewlett Packard ◽  
Conventional Laser ◽  
Scanning Electron

We demonstrated rapid prototyping of templates for replica molding using a conventional laser printer. A polymer, polydimethylsiloxane, was cast directly on the transparency templates to make the replicas. The templates and replicas were characterized by scanning electron microscopy, profilometry, and optical microscopy. Four patterns, including an Electronic Industries Association resolution test pattern, were printed on transparencies at 600 dots per inch on a HP LaserJet 4M printer (Hewlett-Packard, Palo Alto, CA). Optimal precision and clarity occurred between intensity settings of 50–100. Mean pattern height/depth ranged from 8–13 μm, and width was as small as a few tenths of a millimeter. Mean surface roughness of the template patterns ranged from 1 to 4 μm on the top surface and from 5 to 10 nm on the bare transparency surface. This method provides access to microfabricated patterns for the broader research community without the need for sophisticated micromachining facilities.

Scanning electron microscopy used to measure the feature dimensions of a nanoscale test pattern on a silicon surface

2011 ◽  
Vol 40 (6) ◽  
pp. 436-440
Author(s):  
V. P. Gavrilenko ◽  
Yu. V. Larionov ◽  
V. B. Mityukhlyaev ◽  
A. V. Rakov ◽  
P. A. Todua ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silicon Surface ◽  
Test Pattern ◽  
Scanning Electron

Creation of electro-conductive paths and patterns by screen printing on textile bases

2016 ◽  
Vol 88 (3) ◽  
pp. 261-274 ◽  
Author(s):  
Barbara Filipowska ◽  
Błażej Wiśniewski ◽  
Lucyna Zawadzka Michalak
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Screen Printing ◽  
Surface Resistance ◽  
Microscopic Analysis ◽  
Raw Material ◽  
Energy Dispersive ◽  
X Ray ◽  
Scanning Electron

This article presents a number of possible approaches to creating electro-conductive paths and patterns on flat textiles with various structures and raw material compositions. A modifier was selected and the process of creating the electro-conductive paths by screen printing was optimized. The result of this process was evaluated by the measurement of surface resistance and by microscopic analysis using scanning electron microscopy with energy dispersive X-ray spectroscopy. The durability of the obtained effect was evaluated by analyzing electro-conductive paths after multiple washing cycles and after rubbing.

Effect of Silanization Film Thickness in Soft Lithography of Nanoscale Features

2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Lucas H. Ting ◽  
Shirin Feghhi ◽  
Sangyoon J. Han ◽  
Marita L. Rodriguez ◽  
Nathan J. Sniadecki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Beam ◽  
Electron Beam Lithography ◽  
Soft Lithography ◽  
Critical Parameter ◽  
Lithography Process ◽  
Fluorinated Silane ◽  
Nanoscale Features ◽  
Scanning Electron

Soft lithography was used to replicate nanoscale features made using electron beam lithography on a polymethylmethacrylate (PMMA) master. The PMMA masters were exposed to fluorinated silane vapors to passivate its surfaces so that polydimethylsiloxane (PDMS) did not permanently bond to the master. From scanning electron microscopy, the silanization process was found to deposit a coating on the master that was a few hundreds of nanometers thick. These silane films partially concealed the nanoscale holes on the PMMA master, causing the soft lithography process to produce PDMS features with dimensions that were significantly reduced. The thickness of the silane films was directly measured on silicon or PMMA masters and was found to increase with exposure time to silane vapors. These findings indicate that the thickness of the silane coatings is a critical parameter when using soft lithography to replicate nanoscale features, and caution should be taken on how long a master is exposed to silane vapors.

Effect of Layering Techniques on Polymerization Shrinkage Stress of High- and Low-viscosity Bulk-fill Resins

2020 ◽  
Vol 45 (6) ◽  
pp. 655-663
Author(s):  
A Tsujimoto ◽  
CA Jurado ◽  
WW Barkmeier ◽  
ME Sayed ◽  
T Takamizawa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Clinical Relevance ◽  
High Viscosity ◽  
Shrinkage Stress ◽  
Polymerization Shrinkage ◽  
Low Viscosity ◽  
Aluminum Block ◽  
Scanning Electron

Clinical Relevance The use of layering techniques is still advisable with many bulk-fill resins and should be the default unless a particular resin is known to not need it. SUMMARY Objective: The purpose of this study was to investigate how layering techniques affect polymerization shrinkage stresses of high-and low-viscosity bulk-fill resins. Method: Six high-viscosity and six low-viscosity bulk-fill resins were evaluated. Aluminum blocks with a mesial-occlusal-distal (MOD) cavity were machined and randomly divided into groups for different filling techniques (bulk-fill vs horizontal layering vs oblique layering) and further subdivided according to type of resin (high- vs low-viscosity). The cuspal deflection resulting from the polymerization of bulk-fill resin bonded to a MOD cavity within an aluminum block was measured with a digimatic micrometer. Scanning electron microscopy analyses of tested resins were also conducted. Results: In the high-viscosity bulk-fill resins, cuspal deflection of the MOD cavity ranged from 11.2 to 18.2 μm with the bulk-filling technique, from 10.7 to 15.5 μm with the horizontal layering technique, and from 10.9 to 15.2 μm with the oblique layering technique. In the low-viscosity bulk-fill resins, cuspal deflection of the material ranged from 9.2 to 19.8 μm with the bulk-filling technique, from 8.2 to 15.7 μm with the horizontal layering technique, and from 8.4 to 16.4 μm with the oblique layering technique. Conclusion: Cuspal deflections for some high-and low-viscosity bulk-fill resins were significantly reduced by using layering techniques, but the resultant improvement of layering techniques was not applicable to all the bulk-fill resins used in this study.

scholarly journals Pengaruh Suhu Pembakaran terhadap Karakteristik Listrik Keramik Film Tebal Berbasis Fe2O3–MnO–ZnO untuk Termistor NTC

Wahana Fisika ◽  
2016 ◽  
Vol 1 (2) ◽  
pp. 111
Author(s):  
Puspita Sari ◽  
Dani Gustaman Syarif ◽  
Wiendartun Wiendartun
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Screen Printing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Vehicle ◽  
Scanning Electron

Pembuatan keramik film tebal berbasis Fe2O3–MnO–ZnO untuk termistor NTC dari campuran Fe2O3 50% mol, MnO 25% mol, dan ZnO 25% mol telah dilakukan. Campuran serbuk Fe2O3, MnO dan ZnO yang telah digerus dicampurkan dengan organic vehicle (OV) untuk membentuk pasta. Kemudian pasta dilapiskan di atas substrat alumina menggunakan teknik screen printing  untuk membentuk film tebal. Film tebal mentah yang diperoleh, dibakar pada suhu yang berbeda yaitu 1000°C, 1100°C, dan 1200°C selama 2 jam. Sebelum dilakukan pengukuran resistansi, film tebal dilapisi perak terlebih dahulu sebagai kontak logam.  Resistansi termistor diukur pada suhu 40°C–200 oC dengan beda suhu sebesar 5 oC. Analisis struktur kristal dan struktur mikro film tebal masing – masing dilakukan dengan menggunakan X – Ray Diffraction (XRD) dan Scanning Electron Microscopy (SEM). Hasil analisis karakteristik listrik termistor yang dibakar pada suhu 1000 °C, 1100 °C, dan 1200 °C menghasilkan konstanta termistor berturut – turut sebesar 7700 K, 6995 K, dan 5701 K. Ketiga suhu pembakaran menghasilkan nilai konstanta termistor yang memenuhi kebutuhan pasar. Analisis struktur kristal menggunakan XRD  menunjukkan bahwa keramik film tebal memiliki dua struktur yaitu struktur spinel kubik dan hematit heksagonal. Analisis struktur mikro menggunakan SEM  menunjukkan bertambahnya ukuran butir sesuai dengan meningkatnya suhu pembakaran dengan ukuran butir film tebal yang dibakar pada suhu 1000 °C, 1100 °C, dan 1200 °C berturut – turut adalah 1.3 μm, 2.0 μm, dan 2.4 μm. 

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

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