Comparative Study of Thick Film Dielectrics

1982 ◽  
Vol 1 (1) ◽  
pp. 11-16 ◽  
Author(s):  
W. Vermeirsch

Increasing density requirements urge the thick film hybrid manufacturers to print high resolution patterns and to consider the application of multilayer hybrids. The introduction of compact interconnection technologies such as TAB and chip carrier will no doubt accelerate this process. Paste manufacturers are carrying out research to develop inks suited for fine line printing. The properties of dielectric pastes, necessary for multilayer applications, have not been studied so extensively. A programme was initiated to compare various dielectrics in combination with various conductors. From the test programme two tests were found to be most significant for the dielectric's characterisation. These tests, in combination with an SEM‐study of surface and bulk porosity, permitted a quick and reliable selection of an appropriate dielectric paste to be made.

1983 ◽  
Vol 10 (4) ◽  
pp. 295-309
Author(s):  
Walter Vermeirsch

SEM–observation and analysis provide a quick and reliable method of predicting the cross-over and multilayer characteristics of a dielectric paste. Surface and bulk porosity, flow behaviour and chemical composition, determined by SEM are closely related to the results of electrical and environmental tests. From the latter, voltage breakdown and humidity tests should be selected as most suitable for the comparison of various systems.


Author(s):  
M. Müller ◽  
R. Hermann

Three major factors must be concomitantly assessed in order to extract relevant structural information from the surface of biological material at high resolution (2-3nm).Procedures based on chemical fixation and dehydration in graded solvent series seem inappropriate when aiming for TEM-like resolution. Cells inevitably shrink up to 30-70% of their initial volume during gehydration; important surface components e.g. glycoproteins may be lost. These problems may be circumvented by preparation techniques based on cryofixation. Freezedrying and freeze-substitution followed by critical point drying yields improved structural preservation in TEM. An appropriate preservation of dimensional integrity may be achieved by freeze-drying at - 85° C. The sample shrinks and may partially collapse as it is warmed to room temperature for subsequent SEM study. Observations at low temperatures are therefore a necessary prerequisite for high fidelity SEM. Compromises however have been unavoidable up until now. Aldehyde prefixation is frequently needed prior to freeze drying, rendering the sample resistant to treatment with distilled water.


Author(s):  
D.F. Bowling

High school cosmetology students study the methods and effects of various human hair treatments, including permanents, straightening, conditioning, coloring and cutting. Although they are provided with textbook examples of overtreatment and numerous hair disorders and diseases, a view of an individual hair at the high resolution offered by an SEM provides convincing evidence of the hair‘s altered structure. Magnifications up to 2000X provide dramatic differences in perspective. A good quality classroom optical microscope can be very informative at lower resolutions.Students in a cosmetology class are initially split into two groups. One group is taught basic controls on the SEM (focus, magnification, brightness, contrast, specimen X, Y, and Z axis movements). A healthy, untreated piece of hair is initially examined on the SEM The second group cements a piece of their own hair on a stub. The samples are dryed quickly using heat or vacuum while the groups trade places and activities.


2021 ◽  
Author(s):  
Mohammed Gamal ◽  
Ibrahim A. Naguib ◽  
Dibya Sundar Panda ◽  
Fatma F. Abdallah

The competencies of four greenness assessment tools were tested. AGREE is the best greenness tool while NEMI is the poorest one. AGREE, GAPI, and ESA are reliable greenness tools.


2015 ◽  
Vol 16 (1) ◽  
pp. 50-70 ◽  
Author(s):  
Jakob Cakarnis ◽  
Steve Peter D'Alessandro

Purpose – This paper investigates the determinants of credit card use and misuse by student and young professionals. Critical to the research is the impact of materialism and knowledge on selection of the appropriate credit card. Design/methodology/approach – This study uses survey research and partial least squares to investigate credit card behaviors of students versus young professionals. Findings – In a comparative study of young professionals and students, it was found that consumer knowledge, as expected, leads to better consumer selection of credit cards. Materialism was also found to increase the motivation for more optimal consumer outcomes. For more experienced consumers, such as young professionals, it was found that despite them being more knowledgeable, they were more likely to select a credit card based on impulse. Originality/value – This paper examines how materialism may in fact encourage some consumers to make better decisions because they are more motivated to develop better knowledge. It also shows how better credit card selection may inhibit impulse purchasing.


2012 ◽  
Vol 8 (2) ◽  
pp. 228-240 ◽  
Author(s):  
David Hunter ◽  
Hao Yu ◽  
Michael S. Pukish, III ◽  
Janusz Kolbusz ◽  
Bogdan M. Wilamowski

1985 ◽  
Vol 56 ◽  
Author(s):  
L. A. KOLODZIEJSKI ◽  
R. L. GUNSHOR ◽  
N. OTSUKA ◽  
C. CHOI

AbstractTwo epitaxial orientations [(111) and (100)] of CdTe are grown on (100) GaAs in the presence of a 14.6% lattice mismatch. Consistent nucleation of a selected orientation is achieved by employing specific growth techniques. The growth techniques for selection of both orientations are described. High resolution electron microscopy has been used to investigate the interface between the CdTe epilayer and the GaAs substrate. For the (111) orientation strong interaction exists between the epitaxial deposit and the substrate, whereas a weakened interaction between deposit and substrate induces the (100) orientation.


Sign in / Sign up

Export Citation Format

Share Document